I'd live forever, I mean think about it, sure my friends and family will soon die and be gone, but that doesn't mean I can't make more friends and start many families. I would take the opportunity and become immortal, I'd spend years perfecting every skill I can think of. Piloting aircraft, playing many many instruments, singing, dancing, wood carving, drawing, anything at all. I'd be entertained for many a century. Sitting and watching humanity as it either grows or fails? Sounds pretty fun to me. After a long long time perhaps I would end my own life, should I finally acomplish my goal at being the best at everything ever. of course, not without training many students and people and giving them my wisdom that I should have gained over the centuries. Help them out, maybe point humanity in a good direction, assuming I know what a good direction would be. Maybe I'd even live long enough to become a villan.