I got out of the Army in 1992, and was sent to SF for out-processing.
Due to my circumstances, I had about $10, and couldn't draw from my pay, including the nearly 60 days of leave I never used (they pay you for you days you do not use).
So I'm walking off base, and a bum comes up and asks me for money, and I reply "I'm just getting out of the Army, I don't have any money man," and I laughed.
He replied something like "no shit? I was in Vietnam" and we got talking. Dude took me along and showed me how to bum money off people, including getting into a cab and asking the cab driver for a buck... never asked anyone for anything, and this guy kinda took me under his wing.
We gathered about $60 and ate well, had a few drinks, and it is something I'll never forget. One of those defining moments in life that made me a believer in good human decency, even if it was at the expense of a dollar or two from some entitled rich wanker.
Learned a good lesson that day. Looks can be deceiving, and every bum/hobo/homeless person isn't just out there to take money for themselves.