I'm finishing college and kind of feel like its too late for me. I was a shy quiet kid all through elementary school, but I moved in 6th grade and had a chance to reinvent myself as a wild class clown. I had quite a few attractive popular girls literally chasing me, but nothing serious came of it. I had the good luck to read Don Juan Bible in 2005, before PUA became public, and I could have used it to my advantage. But I figured I was already doing cock comedy, by being funny and hard to get. And I was under the illusion that all I had to do is keep working out, and if I reached a certain level of fitness I would win a girlfriend like a trophy.

Anyway after missing the dating scene all through high school and college, where it supposed to be so easy for anyone to have a harem, unless you're a complete loser omega, I kind of feel hopeless. I made a few PUA attempts in college and did some winging, and nothing worked. It seems as I get older my social opportunities will get even narrower since I wont have the same easy networks with females that school provides, and the workplace will provide far fewer social contacts.

Plus I feel like I missed out on a lot of the excitement of a boy having his first girl, that comes in the boyhood/ teen years, that feels meaningless and pathetic to a guy in his mid-20s.

Never too late buddy

Dude, there are guys who started looking at PU in their 50's!
Tyler Durden from RSD mentioned a guy who came to one of his bootcamps who was 55 in one of his seminars.
You're constantly changing, whether you're aware of it or not, and more often than not you have no idea where you're going or how to get there. Studying PU helps with that by giving you many routes to take to slowly start reaching your goal.
The question isn't whether its too late or not but rather whether you're willing to commit to improving yourself and willing to change.