There is a golf course a couple miles from where I live and I used to go fishing at a pond there, usually first thing in the morning.
There used to be a guy named Daniel who would come every morning and do maintenance work. It's an 18 hole golf course, really big. He had a morning routine of things he had to do including mowing the grass, putting up the flags at each hole, etc.
He's a really nice guy
. We often chatted about different things and we got used to seeing each other there. This morning, I decided that I would do something for him. So, I drove down to the golf course at about 6:30 am and got all the flags for the golf course (which they keep outside by the clubhouse) and went and put them up at each of the holes. This is one the main things he had to do each morning and, as you can imagine, it could be quite time consuming at such a large golf course.
He usually gets there at around 7:30 or so. I didn't stay to see him find that someone had done that for him, and didn't leave a note or anything to let him know who did it, it actually feels really nice doing something for someone and not taking any credit for it, just being happy for helping someone.