You weren't a good citizen, Stealing was a good thing that was fun for you, victimless crime by Gotham standards. But one night you had a little too much fun, you cut yourself on the window while trying to escape but failed, they put your fingerprints and DNA into the system. You were sent to jail, You sat in the cell wondering who to call. You really had no one.
After a few hours they let you go, they said someone came to get you, you had no idea who it was considering you didn't tell anyone where you were. When you left the center, there was no one there, was it a mistake?
But still, to take precautions to prevent yourself from becoming a bigger threat, Batman invites you to live at Wayne Manor, you accept, without really having anywhere to go. You already had the hunger for chaos, the need for risky activities and the skills to become a huge problem, All you needed was someone to guide you in the right direction, who better than Batman?
3 months after living in Wayne Manor and you were struggling with withdrawal from stealing, you felt little satisfaction when stealing from your peers, You needed something bigger and it wasn't allowed... struggling with school, you had private teachers for each subject, it was a little annoying that Bruce wouldn't let you stay at your old school. Even though it was an environment ripe for criminals, at least you had people there.