Sirius had never been the favourite in his family, it had always felt as if they were just enduring his presence. The main focus was always on the rest of the family, his brother Regulus and even all the distant relatives. That when they came to visit they were treated preciously and Sirius was told to only speak when spoken to and serve the food.
Only because they thought he didn't live up to the Black family name, a line of pureblood wizards that had great respect and honour with the other wizarding families. Although they had never agreed with the terms that the Dark Lord used they had respected his wish to have a world of only purebred wizards. Sirius however, had disagreed completely with their methods.
All throughout his childhood he had to endure his family, they were greedy, unkind and horrible to live with. So when the day family came for Sirius to start school at Hogwarts he was overjoyed. He wouldn't have to see his parents, and he only had to put up with his brother who would probably just ignore him anyway.
He met James on the first day of school, on the Hogwarts Express. It was like they were both drawn to each other, meant to be friends.