If I were in your position I would leave it alone. I say that because there is nothing, really, to be gained for me by saying anything to him. There are plenty of bald icons out there that if he hasn't gotten the message by now on his own a more pressing matter would be stronger eyeglasses.Plus, I find this practice that I might refer to as "Sly Evangelism" to be really kinda, for lack of a better word, boring. Sort of brings to mind people who quit smoking or drinking after decades. They tend to evangelize in the hope of recruiting converts. It's almost painful to go somewhere that this person is going to be because you just know that at some point they're gonna start. And since you didn't indicate that young "Bozo" has asked for input I would make the assumption that he doesn't want any. In the long run this is not a religious experience or an adventure of some kind.....it's a haircut. And sly ain't gotta be sold because sly sells itself.
Thanks everyone for advice and I will look the other way. I know how I felt with premature thinning and someone's comments. Everything works out in its own way(s).