The day Hermione came back from her Hogwarts graduation pale and shaking he knew he made a mistake. It was a mistake he couldn't and wasn't entirely sure he wanted to turn back from however. Now, after everything, magic was a part of what he was.
"...And then, like in that one story where that girl didn't have a shadow because...Professor McGonagall said 'Let the devil take the hindmost' and all the purebloods scattered, and then..." Hermone said as she sobbed into his shirt, having just witnessed the demise for the lack of a better word of a Ravenclaw who'd been a year behind them.
He should've known. Something as great and wonderful as magic always always always came with a price.