What to do about the one who got away...?

13 years later. The was this guy I was good friends with in high school. He was a huge geek, I wasn't popular but I also wasn't unpopular, so I never gave into feelings I had for him. He was such a great guy a real gentleman and even after 13 years I find myself regretting not giving him a chance. Has anyone else had these feelings or been in this situation. What do you think I should do? Try and find him or... 13 years later and I've never had a bigger regret.