It was very kind of you to try and do something for him.
As other pp have said, he would have had complex issues with alcohol/drug problems probably, and wanted money to get a fix. Unfortunately a lot of homeless take drugs, and whilst I would not begrudge them spending the little money I give them on drugs, I do not want to be funding the drug industry.
The charities ask us not to give money to the homeless and it does not solve anything. In fact it can contribute to making things worse. A lot of the homeless die on the streets, especially when it is cold. Alcohol and drugs can contribute to this.
Thinking of how rude he was to you, think about some of the things he puts up with on a daily basis, he probably gets spat on, sworn at and pissed on. He must have a horrid life.
On average, homeless people die at just 47 years old. A homeless rough sleeper is 35 times more likely to commit suicide than the average person.
The streets are a dangerous place to be - homeless people are 13 times more likely to be a victim of violent crime than the general public, and 47 times more likely to be a victim of theft.
St Mungo's are a great charity that help and support the homeless. Next time make a donation to them, they are helping to make a difference to the homeless.