Compared to the first verse of "Ride My See-Saw" ("I worked like a slave for years..."), the chord progression for the second verse ("Left school with a first class pass...") is different. The first verse is
|: C major | Bb major | F major | G major :| Bb major | C major
but the second verse is
|: C major | Bb major | F major | G major :| Bb major | D minor
Part of this difference seems to be because the first verse transitions into a different iteration of the chorus ("Run, run my life's race...") while the second verse transitions into an instrumental section, but putting a D minor where a C major is expected is also something of a musical representation of the lyric there: "School talk one and one is two / But by now that answer just ain't true." It's as if the song goes to a different chord (and a minor chord, at that, where everything up to this point has been a major chord) because "by now that answer just ain't true."
