I have a theory I just formulated while in the shower
I am high, so naturally, my shower was longer than usual. As such my fingers began to be pruned. If you are unfamiliar with which I speak of, it is simply the natural ridges your fingertips and toetips that form after being exposed to water for an extended period of time.
Theory Behind Why Our Tips Prune
I state that the reason we experience this is because of an evolutionary adaption that helps us clean ourselves.
I say this because as I was applying shampoo, I noticed the newly improved prune fingers assisted in the application very much.
It also explains why they only get pruned once prolonged water is applied.