In Holland all the 'bums' are drugs addicts. So I never give them anything, cause they'll sniff up their money the very same day.
One time this guy pulled out a gross story and showed me his infected arm that needed medical attention. He smeared some pus on the floor next to where I sat.
Another time a guy had a touching story of how he needed to take the train to go to his dying mother in hospital. He asked me if he could borrow some money. He told me where he lived, so I could get my money back.
When I told that to my friends, they said they knew the guy because he had done the same thing to them.
I never checked if he really lived where he said he did.....
