Yeah, I get the impression that he was a bit of a loner and although he WAS a bit of a genius, she contradicts that by calling him foolish and stupid for what he did (committed suicide). So the lake is a place where all the kids swim, hang out, have sex in, etc. He goes in there to experience a different kind of orgasm - death. He takes his clothes off and drowns himself. He hopes his death will make him get noticed, but no one really gives a shit (she talks about the neighbours starting their cars & going to work, the kids waking up with hangovers, bin men emptying the bins which hold his clothes, etc - just carrying on with their lives, basically) and so it was all for nothing, pretty much.
Dunno if that helps or if it's right, but that's what I got from it.
I love it.
"Carbon Monoxide" is similar kind of...she talks about a couple who make a suicide pact.