I started thinning at 21 or so, at least that's when I noticed it. Here I am almost a decade later, and while it's obvious I'm thin on top, there is still something up there. Different people lose at different speeds. Some will lose all of it within 3-4 months (happened to a buddy of mine). People like myself, it's a slower and gradual loss.
But, the power is what you give it. If you want to be self conscious about it, then that will show through and you'll come off as inhibited in everything you do. If you don't care, then you'll be confident and that shows through as well. If you really want to go the route of treatments, that's your choice, obviously.
But, just keep it nicely trimmed close to your head. Easy maintenance, covers it up as much as anything possibly can, and you will look like a bad ass (unlike some of the other guys you posted above...Bruce Willis being one of them!).