Q: Why do the key changes at the prechoruses of "we could just get high" not follow a pattern? (D to A, D to C#, G# to Bb)
A: why would they follow a pattern? the human listener notices how it feels, not how it looks when you analyze it on paper.  it's kind of like how stories have twists and turns and surprises. Actually, i was stumped on this song for months -- i had verse 1, cho, verse 2, and just was losing momentum in the second chorus --- that was before i had the idea for the second key change. then all of a sudden it occured to me to put the second chorus in a much different key, and that really sparked the right feeling at that point in the song. The first chorus already sort of had that effect (raised a whole step), and it was a natural continuation of the 'liberating/escape' feeling to have the second chorus be unexpectedly even more adventurous. From that point on, it was just a delicate balance of where i thought it should go next, and i just listened carefully to where it wanted to go from there, and the song was finished very quickly