Im guessing it was stolen.
A friend gave it to me after an ex boyfriend abandoned it at her house. my roomies and I fixed it up( b-12 the carbs,charge the battery) and then I forgot about it, A trip to the mountains and many many beers later I think to myself " Oh yeah !I have a motorcycle so I go outside to ride it and it was gone. I also lived in a place that had private parking and since we didnt sticker the bike it might have been towed as well. Since I had no proof of ownership it was chalked up to a lesson learned.
Now 18 years later I dont think I will forget ownership of a motorcycle ( irony is same thing happened with a 70s eldorado as well!)