Harry Potter is the Master of Death, and thus, immortal. Every couple thousand years, he'll let himself reincarnate into a new dimension. This dimension is quite similar to his first one, except he has a twin brother, and the Voldemort in this world is willing to give up everything he's worked for, as long as Harry teaches him magic. And Harry? Harry just likes annoying Voldemort with memes, vines, and Potter Puppet Pals.

Post war Harry finds himself devoid of any goal. To know what he should do now he goes to room of requirement and through vanishing cabinet he descends to past. de-aged and lost Harry finds himself in front Wool's Orphanage in the summer of 1941. That is why its said think what you ask for. you might get exactly that.