it is my experience that in most cases teachers are never fully qualified or trained for whatever it is they are teaching, and instead they rely on what little experience they have (possibly from the teaching itself) and the course materials to carry them through their career.
sorry you had such lousy teachers.
here is my PC story along with a bad teaching experience:
freshmen year of high school, first class, Computer Applications. which was about 30 Mac Classics all networked.
they were running system 6, and were locked out in the sense you couldnt change anything, names, files, etc, except in your own folder on the network. you couldnt rename the HD or any files....
my friend and I realized if you put in a disk, clicked to change its name and then click the HD to change its name, it would let you!
so we changed EVERY computer HD's name to something obscene and childish, it was high school, gimme a break.
this was on a friday.
monday comes and the teacher sits me and my friend down, grabs our disk (which was just a 3.5" disk i had lying around) and says:
"WHATS ON THE BOOT SECTOR!!!!?"
he goes on to explain he spent the entire weekend trying to rename the HDs and he couldnt do it.
we showed him how we did it, in 10s and he was floored.
the rest of the semester we all just played Net Trek, Sim City and Othello, NOT a single piece of schoolwork got done, because he had been humiliated by "lowly students" who shouldnt know more than the teacher.
another story, same setup, was that apparently Mac Classics have 2 buttons on the side, one resets it the other does NOTHING....until you press it while starting up.
we would restart the computer(s) and immediately press the (what we called) "Drunk Button" which caused the screen to invert to black with a very sad and dead looking mac icon.
"OH MY GOD NOW THEY'RE ALL DOING IT!? WHATS GOING ON!?" he said. We did this every day at the end of class bell to at least 5 machines.
he quit/fired that year.
fast forward a couple of years.
my mother, who teaches at a different high school, tells me "you remember your teacher Mr. XXXXXX ? hes our schoolwide IT guy"
I almost died laughing.
he still has that job to this day, and from what my mom tells me, he truly is an idiot.