I like this tennis ball because it is pink. All my other tennis balls are green. You're probably thinking, why does it matter if the tennis ball is pink? And I don't really have a great answer, beyond that it just feels kind of special. I love every time I grab it, like: green, green, green, surprise! Pink. It makes me smile. The origin story is that I found it on the court one day, left behind by some other player. It was sort of dirty, and in the corner. I picked it up and cleaned it off and have been using it ever since.
At this point, I consider it kind of a good luck charm.