Sirius did not wish to remember his childhood as he trained to be an auror and an Order member.
In truth, he never wished to remember it at all. He learned dark magic by being on the other side of it, it was how he learned his manners too. His mother always so cold, his father barely there.
But as he trained to kill those like them, this was not why he wished he couldn't remember.
He wished he couldn't remember the wild, happy laugh of his cousin Bella, before Rodolphus had broken her.
Wished he didn't remember the sly smiles of Lucius Malfoy as he lied to protect him from his mother when he had broken her vase.
Wished he couldn't recall Narcissa finding him crying and comforting him as he recovered from his first taste of the Cruciatus.
But above all else, he wished he didn't remember his little brother's wide, gray eyes, looking at him with love as he protected him from their parents.
He knew if James hadn't come along, if he had a slight bit less courage, if he had listened to his mother and sat with Bella and Cissy that day.
He would be just like them.
They were just victims of circumstance.
Faultless, in a way.
And Sirius wished like hell that he didn't remember that.