Have I done something positive about someone to their face?

There is an older gentlemen who comes into the C@P site here at VANSDA. He comes in once a day, usually about twice a day. He rarely uses the computers, he reads the paper and waters our plants- its sweet. He always has a grumpy look on his face, like he's mad at the world, but I think it's more of an act. So today when he came in, I said "Hey, (anonymous) we really appreciate all the little things you do around here, I love when you come in everyday!" He kind of grunted, and waved me off like he didn't care, but when he left, he made it a point to come over to me and say "have a good weekend".. with a half smile on his face. He never says goodbye, just comes and goes. That's the first smile I've seen from him :)