Another burning question

So SM wears boxers. I've noticed that several pairs of his boxers have pockets. Not small patches of fabric attached to the leg or back but full pockets sewn into the seams of the boxers on the sides, the kind that you could put your hands in. Except that they aren't really deep enough for anything more than maybe a deck of cards. And no, the pockets don't reach around.

So, I just wanna know why? Why would anyone need pockets on their underwear?