Lyric discussion by Telecaster 

Cover art for Cuckoo Cuckoo lyrics by Animal Collective

Unless they really did have a son who died.... There is no doubt in my mind that this song is about depersonalization/derealization disorder (DP/DR). This even makes more sense to me.

For anyone who's ever had it, these lyrics are dead on for how it feels - hence also the title of the song, Cuckoo Cuckoo. It can often come on suddenly after tripping, never fully returning to reality in a sense. You feel like reality, emotion, everything is just torn away from you and like you'll never be normal again. Inner-death as he's putting it here. Ego-loss too, it's ALL there.

I could list quotes, but its basically the entire thing. It is about dp/dr.