My friends, the people who read this first, were wondering what I meant when Sirius said "I've lived here for 16 years...". He ran away from home , at 16, to move in with the Potter's (James and his parents). So 16 years. And, yea, I know, Sirius hates to read books, he's the cool-but-still-passing kid and he would rather play pranks and quidditch than study, but I wanted him to have something in common with Hermione. I wrote this before the 5th book, so it's not compatible with 5, 6, or 7. Hermione's 19 or 20, I never did figure out her actual birthday so I can't tell you exactly, but that makes Sirius 39 or 40.