I think this is a myth. Or maybe I'm just an adolescent stuck in a grown man's body. I keep waiting for the day when my sex drive subsides, and I can get some focus in my life. But so far, two decades after hitting puberty, it hasn't really started to wane yet. It's a curse and a gift, I suppose.Sex. Lots and lots of sex. Don't know how old you are but frankly, the younger you are, the more of it you'd probably have.
What I have found is that the time spent having sex does not necessarily change, nor necessarily the drive... but the number of times you go in a day decreases. I have a couple of male friends in their early 30s who say they still have the same drive. Basically I think I am saying quality goes up but quantity may go down a bit. I'm just sayin', like, I ain't havin' sex five times in one afternoon anymore. And yeah, I'm sure miles vary.
Obviously, people have different sex drives but, it seems like it can be tied to a person's level of physical fitness. If I'm in really good shape, I have a really high sex drive. If I haven't been working out for a while, then it diminishes a bit. Someone must be studying this, somewhere.