Matty Pemulis's birthday, and Da — "It was years before he snapped…"
It was years before he snapped to the fact that his Da’d have fooked him in t’boom no matter what he’d done. That the event was laid out before the first slim line of doorlight broadened, and whatever Matty’d felt or betrayed made no difference. An advantage to not blocking it out is you can snap to things later, with maturer perspective; you can come to see no sone on the planet could in any way ask for that, regardless.
Context
Mid-recall, the one consolation of unblocked memory is named as an "advantage": because Matty forgot nothing, adult perspective can go back over the record and acquit the child — nothing he did or didn't do would have mattered. Memory as the raw material of later understanding; the passage argues, grimly, for remembering. ("sone" as written.)