It feels like he tried but failed at suicide. When he "forgot to be vain" I think he's saying he missed the vein. When he says, "Everything just bleeds" I think that's his excuse for cutting himself, thinking he did it right because blood was coming out, even though it wasn't a fatal wound... Then elsewhere he's talking about it not be his "last try" and "maybe next time is never" as if he still intends to pull it off eventually. He "sent it off in a letter" ... suicide note? The idea of failure is also amplified by apparently missing the wishing well when he tossed a penny. etc.
It feels like he tried but failed at suicide. When he "forgot to be vain" I think he's saying he missed the vein. When he says, "Everything just bleeds" I think that's his excuse for cutting himself, thinking he did it right because blood was coming out, even though it wasn't a fatal wound... Then elsewhere he's talking about it not be his "last try" and "maybe next time is never" as if he still intends to pull it off eventually. He "sent it off in a letter" ... suicide note? The idea of failure is also amplified by apparently missing the wishing well when he tossed a penny. etc.