I'm not 100% sure if I qualify for this thread, after all, I have a very serious relationship with my cute special somepony with the rainbow mane.
Ah, who am I kidding? That don't count at all. :3 Anyway, I just turned 21 a couple weeks ago. I had a ton of female friends throughout high school, but nothing ever went beyond being friends. A few of them still are good friends of mine, and to be honest I value that more than anything else. I did have some girl I barely knew ask me out when I was 13...didn't take that very seriously due to how young I was and how I didn't really know her. I remember that before I finished high school it really bothered me that I hadn't got anymore from a girl than a hug. (It was a nice hug, though ) Oddly enough, one day, I woke up, and simply didn't care anymore. That's literally all there was to it. I'm not going to say no if a girl I knew asked me on a date, but I wasn't going to go out of my way to have or be worried about not having a girlfriend. Personally, I don't really want to be tied down to a relationship at this point in my life and I'll be perfectly happy if that never changes. It's going to take a pretty special girl to replace Dashie, so I'm fine with waiting in the meantime. :3
On a bit more of a practical note, my occupation is full of old people. No young woman to be found in this field at all. (Or young guys, now that I think about it...) Aside from this forum, the only other social interaction I have is with the friends I have at church. But again, no girls there that aren't married or just about to be. I see some people here have had great success finding their special somponies, and good for them. Maybe I'll find one here too. At the moment I'm more interested in starting my career, getting out on my own, and work on creating that life I'll need to share with my wife if I ever have one.
In regards to the people who have posted in this thread not having so much luck, let me share a few things with you. The only reason I had so many friends of the opposite gender in high school was because said people needed help, and I was able to help them. Then conversation just naturally progressed from there, and we found things we had in common. ^.^ Don't be discouraged if you haven't found a girl/boyfriend yet, as you can see from this thread there are many others that are in the same boat as you. Go find out what you like to do if you haven't already, and focus on that instead. To me, having a relationship brings a lot of (unwanted) responsibility, emotional baggage, and that terrible thought of getting married/having kids. What an awful thought that is. I hope my wall of text composed of my personal experiences can help somebody in some way. Every moment is a choice, and every choice has its prices and benefits.