Are you always that generous?

A man got on the bus, the fare was $1.50, he only had bills... no change. He asked me if I had change for a dollar. I did not. I did however have 50cents. So I offered it to him. He thanked me, paid the fare, and sat down. The rest of the ride was uneventful until we reached my stop. As I stepped off the bus, the driver asked me, "are you always that generous?" I thought it was an interesting question, because I didnt think I had done anything generous. My answer..."If I do something nice for him, maybe he'll do something nice for someone else." It is amazing to me that the act of giving someone 50 cents is considered generous.