David got lucky.
(He knows enough languages to get by. He's trained all his life. He is unusually good at gathering mana - not enough that he's really special, but enough that people have commented on it. Not that it's relevant. No one cares if you're good, they care if you're good enough.)
He got lucky because he's not an enclave kid, he just got accepted into their group. (He was going to be carrying shit for them, shit nobody really needs but it'd be nice to have. Shit like letters. Shit like candy, and deodorant. Who brings deodorant to the Scholomance.) So he wasn't in the enclave when - whatever happened. Happened.
He went to the enclave thirty minutes before induction, because he was a couple ounces under and he wanted to make sure nobody had any stupid last-minute requests.
The enclave... wasn't there. He checked another entrance, wasting five minutes, and it wasn't there again. The enclave. Is gone.
So here he is. Twenty-five minutes before induction. No enclave "buddies", not that they'd have done much for him inside. Backpack full of garbage.
He tosses the deodorant, Jason's fidget spinner, the box of Evelyn's durian candy that no one but her would ever eat, everything they saddled him with. He keeps the letters. He's tempted to burn them, but the recipients are still there even if the senders aren't. Maybe he can get more for them by leaning on it. This is the last thing your mother ever said to you, you know.
He breaks into a liquor store. Ignores the blaring alarm. By the time the cops get here, he'll be long gone. He knows exactly what everything he threw away weighs. He's got enough allowance to get three bottles of vodka. He gets the good shit. It's not like it weighs more. He also picks up a box of mixer powder. It doesn't weigh much and it'll help him sell the shit.
David got lucky. He's not going to get lucky again.