Share your kindness story

This is someone else's act.
I was on a bus, and we were already arriving at the destination. There was this indian old woman who was clearly poor and sells crafts. She spent all the trip in a front seat, so would pay the ticket after passing the collector. When she had to leave, the collector asked for the ticket money and she had none. She tried to explain her son who was on the back of the but had already paid but he said he didn't, he had only paid his, and he had no money too. She was busy holding a lot of crafts, and could not speak our language properly and the collector was impassible "so you shall not pass" and a young guy who was waiting for the issue to be solved right behind her to pass too, promptly used his ticket magnetic card to pay her the ticked and she was allowed to pass. Although I was sitting quite far from them and my student card would not be useful here I was ashamed because I don't know if such attitude would come to my mind and I was "why didn't I think doing this before?"