Five years ago, Federer promised a fan to play him. The great kept his word.
Zizu (not that one) was a kid when he first met Roger. The kid made a promise to the tennis player that he wouldn't end his career until they played a match together.
And now Zizou has grown up. Roger was one step away from finishing, but decided not to procrastinate. They met on the court. The guy was wildly ecstatic.