A big part of being an ALT is being disgruntled. Sure, there are ALTs who are not disgruntled, but there are a lot of disgruntled ones too. The job has its stresses, and the biggest ones are the contrast between expectations and reality. Even if you think you know, you really can't know until you know. Intellectual knowledge only goes so far. Your mileage may vary, but the most important thing to remember is that your attitude is what makes or breaks your experience overall: sometimes you will be put into bad situations. You can get frustrated about them, but that will only make you miserable. Life is a lot less enjoyable when you are miserable.
Scenario 1 (JET Propaganda)
You will be part of a team. The junior member, certainly, but you will provide valuable feedback and be an important asset in the classroom. You will play a part in the planning of lessons, and will be respected and well loved by your teachers and classmates who will bask in the joyous glow of internationalization.
Scenario 2 (Bitter ALT)
You'll be some teacher's bitch. You won't ever get to do anything. Your job is meaningless. You're a human tape recorder. Internationalization can go fuck itself.
Scenario 3 (ALT who has purged their bad memories)
Its really wonderful. I loved every moment of it. They're so great about everything. My friends used 'chan' instead of 'san', and everyone really liked me. I felt like I really made a difference.
(Note: 'chan' and 'san' are appended to names in Japanese like 'Mr.' is prepended to a name in English. Using 'chan' would suggest a higher level of closeness between the speakers (or disrespect).)
Reality 1 (My Middle Schools)
I am a part of a team. I am the part of the team who doesn't get told about schedule changes, and doesn't know anything about the upcoming lesson. I am also the part of the team who gets asked to "take up about twenty minutes of class", but is only given five minutes of warning before that class begins. On certain great mornings you run into that scenario two or three times in a row. That is pretty much disrespectful and not an acceptable way to treat a human being. But... it is none the less the reality of the situation.
A lot of people get worked up about the "How the hell can they ask me to prepare half their lesson five minutes before class starts?" I was on that path too, but this morning it happened twice in a row, and I just made do. Its a bad investment of my mental health to get upset about the bad behavior of my 'co-workers' (I doubt they consider me a co-worker, infact this is made somewhat clear by many of their habits of addressing me using 'san' instead of 'sensei', which would be like a slap in the face if I wasn't just some foreigner).
Teaching at the middle schools is not a very rewarding experience. There is very little desire for my input, and I am lacking the experience or laminated piece of paper with fancy seals required to make them value my opinion in the area of education. When I am asked (told) to do something, its usually busy work or done in such a way that my hands are partially tied (need it done in five minutes, extraordinarily vague, unclear time requirements, etc).
Reality 2 (My Elementary Schools)
I am part of a team. The other part of the team is hiding underneath their desk though, so I should probably not count on them for support. I plan all of the lessons myself, and teach them more or less on my own. Some of the home room teachers (the primary instructor that I am assisting... sort of...) do participant in the lessons, but at that point it often becomes an exercise in playing the lesson to the teacher and to the students, instead of just to the students. This is actually the most exciting part of teaching as an ALT though.
When elementary school lessons work out then you're kind of having a casual flow of communication with the primary instructor, and keeping the students interested, all while teaching a lesson you personally created and designed. Where I am there is literally no lesson plan, syllabus, or other source of guidance, so I am free to do anything in these lessons (I suspect it would require a legitimate catastrophe for them to give me some guidance, they simply don't want to have to deal with the English lessons at the Elementary school level). This can be a lot of fun. At first it was nerve wracking to have so little guidance, but now it is pretty fun.
Reality 3 (Elementary at my small school)
At my small school (a total of 14 students in the school), the elementary lessons are really amazing. The classes have 2-4 students in them, and that means I can do almost anything I want. Admittedly this is restrained a lot by the fact that most elementary students have a very hard time recognizing roman characters. But... that means I get to spend time working on recognizing roman characters and doing pronunciation with the students. Flexibility. Since the home room teacher is also there, it means that there are often two teachers and two students in the classroom. This is fun.
This is really a great laboratory for teaching ideas. I have been doing a lot of phonetics (eeeh, its a work in progress), but have also played cards, worked on writing and recognizing roman characters, and a handful of other activities. I am thinking about trying to do some Silent Way style lessons if I can find some proper materials. (Although, the aforementioned inability to read really impairs the value of the Silent Way idea of having vocabulary sheets littered around the classroom.)
You Are A Real Teacher
Scenario 1 (Propaganda)
Yes. Thats right. People will respect you. They won't treat you like an alien, and won't treat you like an incompetent stranger. It'll be great. Oh. But they may resent you for being paid more than the young teachers. But other than that its awesome.
Scenario 2 (Disgruntled ALT)
They won't even speak to you. You will be miserable, and they won't care. They don't hate you, they don't realize you are a human begin and thus capable of hating.
Scenario 3 (Infatuated ALT)
They'll treat you like royalty, its really wonderful. Its like being a rock star.
Reality 1 (My Middle School)
Basically I am ignored, except for when necessary. I once had a teacher pace behind my desk for thirty seconds before finally turning around and having him quickly tell me we have a volleyball practice (for a city wide competition the next week) that evening. Well. I appreciate actually be told of these things, but I don't know why it is nerve wracking to tell me this. Especially since you did it in Japanese.
So... this means that people ignore me because they feel uncomfortable talking to me, I guess. I definitely could do a better job of going out of my way to engage the other teachers, but its never really clear when its appropriate to do so. You are warned that the other teachers are very busy and that you shouldn't interfere.
Its also hard to pretend to be a normal teacher when the other teachers don't address me as a teacher, tell the students not to address me as a teacher, and insist on using keigo (extremely formal language) to address or describe me.
Please relax now that your holy majesty the third Will son of God Larson is here. Now. No, no. Don't call him a teacher. Why aren't you relaxed? I just don't get it. Sigh Lets enjoy English! Yes, lets!
Reality 2 (A nearby ALTs Middle School)
They never speak to me. I corner them in the break room and try to force them to talk to me. Even then they respond in one word answers. They never ask me to come to their classes. I hate my job.
Reality 3 (My Elementary Schools)
The teachers talk to me, and are really pleasant. They treat me like a human being. They don't help me plan, but they don't change their expectations on me without warning. Its a pleasant environment to work in, they really make an effort to be friendly.
The Value of Speaking Japanese
Scenario 1 (Official Propaganda)
It helps to have some basis on the language, because it proves that you are interested in Japan. But you don't have to have any proficiency. We'll take care of you. Oh, sorry, did that sound threatening?
Scenario 2 (Disgruntled ALT without Japanese)
I hate Japanese people anyway. I just get drunk every weekend anyway.
Scenario 3 (Disgruntled ALT with some Japanese)
It helps me get around. Lets me hit on girls in bars.
Scenario 4 (Disgruntled ALT with flawless Japanese)
Just kidding. This person doesn't exist.
Reality 1 (Me with moderate Japanese)
It helps getting around, and it helps in classes in elementary and at my adult conversation class. It is a real boon in daily life. It doesn't really help a whole lot in the office though, it mostly lets me understand people talking about me, but not bothering to talk to me. That experience doesn't necessarily enhance my quality of life in a tangible way.
Reality 2 (ALT with minimal Japanese)
God. I wish I could speak better Japanese. Everything would work out if I could speak better Japanese. I could hold a conversaiton with this cute girl and...
Reality 3 (ALT with no Japanese)
I really wish I could speak Japanese. I hate being reliant on people around me for everything.
The Value of Having a Background in Education
Scenario 1 (Official Propaganda)
It doesn't matter. Don't need it. May help you get accepted.
Scenario 2 (Disgruntled ALT with previous teaching experience)
I wish I didn't know anything about teaching, then I wouldn't want to leap every night walking home across the bridge.
Scenario 3 (Disgruntled ALT without teaching experience)
How the hell do they expect me to conduct complete lessons without any training or experience???
Reality 1 (Me)
It certainly isn't necessary. But I think it would help teachers take you more seriously if you were brave enough to remark that their teaching methods (teach the textbook, only the textbook, and give the same exact quiz three times in a row? Brilliant.) are questionable. I was definitely overwhelmed at first, especially having to teach a 90 minute adult conversation class without any guidance. But it has gotten better, after about 4 weeks of actually teaching, things started to finally click and make more sense.
Reality 2 (Nearby ALT)
I guess it might help if they let me into the classroom.
Reality 3 (ALT with education minor)
I really enjoy when I get to make my own lessons, and I have some experience doing it.