Maybe in the cases where you are the last aggressor and villain asks to show.

But in this case it's pure ego. What strategic reason do you have for showing other than to be like, "Look at me I can fold KK pf! I'm so good!"

Ego? No, not primarily at least, although I can't say I have a definitive window into all of my actions.

In part it was for fun, as was suggested by others. At these stakes, the game should be fun. I also get to be super aggressive and (usually) get away with it. But after a while even the most casual player will notice that I am always betting, raising, check raising and 3 betting. Showing the table I play quality cards, and am willing to lay them down, allowed me to more effectively remain loose aggressive without worrying about getting 3 bet or check raised.

This strategy would not work at 5/10, particularly in Vegas, and I would not show my cards in such a game.

Also, against this specific opponent, I needed him to fear my range more. It worked, too, by the way. I finally got into his head.