the way that i interpreted it was that you were looking back on childhood through the lens of memory. so there is one theme which is pretty prominent - the first time you hear it, that's representative of the time that you spent at school. that theme is constantly being reinterpreted through the entire song, which represents how the passage of time effects how you remember your time at school.
i know this is pretty far from the theme, but... tough theme. so deal with it!
me, starting OHC at a reasonable time: "finally, i'm not starting 30 minutes late! this is ganna be great! im gonna blow everyone's mind!"
me, 30 minutes later: "i hate this idea, time to restart"
I hope you can excuse the many many many errors in this piece. Most of it is raw improvisation with only the barest of fixes :X
i have been doing a lot of piano work recently so... yah