Required charity

So this week I was given the assignment to go, "buy someone a drink." I found it an interesting assignment and it was quite ironic that the teacher's debit card didn't work the day he gave the assignment and someone had actually bought him his lunch. He had already planned on telling us to be charitable and then got to experience the receiving side of charity. Either way I was asked to go and overcome myself. I'm all about doing good to others, but I'm not a fan of being required to do so. It leaves me in quite a dilemma. Should I go out and fulfill my assignment by being charitable to someone, or does being assigned to be good really count as being good? I know it doesn't matter to the person who receives the kindness, but it makes it feel empty for me. I feel bad for the person I didn't help this weekend, but I didn't go to a store or gas station so I didn't really have the opportunity. Going to a store and stalking someone only to buy their stuff seemed a little creepy for me, so I passed on this opportunity. That is not to say that I've never bought someone's food for them, just to do so. I actually like doing stuff like that, it just bothers me when I become required to do it for points or an assignment. It goes against who I am to do it. I'm also not a big fan of telling people about how great I am by helping others, so this assignment was twice as much against my principles. Needless to say I help when I see the opportunity, but I don't like being required to do so. ba humbug!