Really can't resist the ficathons. Neville learned about the prophecy after the War.
Listening to the words, it was clear.
It could have been him. It should have been him? It came quite close to being him. It starts with the birthdays...
He lost his parents - not to death, as Harry, but he lost them to the Dark Lord. It was only the physical mark, as far as Neville knew, that did tipped the scales of fate.
Neville didn't envy Harry the burdens of being The Boy Who Lived, the fame, the expectations, the harassment.
He didn't envy Harry's battle for survival in the TriWizard Tournament (and was quite happy with his own date for the Yule Ball, no need to be a champion).
He didn't envy Harry's year on the run. Running the DA with Ginny was a perfectly good way to spend a war.
But he knows he destroyed the last horcrux, he knows he was so close to the fulfillment of the prophecy, that there are moments where Neville does envy Harry, the boy he almost was.
Neville is convinced that if she'd grown up hearing stories about Neville Longbottom, the Boy Who Lived, Ginny would be marrying him today instead.