Well, I might be able to answer your question somewhat.
When I first entered middle school, I was actually reasonably popular I guess. Like I wasn't in any state of social outcast/misfitting until basically the end of the year when an untrue rumor started about me, then all downhill from there. What happens with me is, I initially appear to people as like, a smart, good looking and sorta "cool" dude, and then when they get to know me they're like "Gee, you're weird." So it makes it hard not to make friends, but to keep them.
But I guess an example is this. When I first entered middle school, I got to sit at much "cooler" tables. Then I just decided I didn't like them. Their conversations were stupid and lame and I knew nothing about what was going on. So I sat at the "nerd" table with some people who very likely could have been diagnosed Aspergers, in fact one guy I think was DXed. So we got to talk about anime and politics, it was sweet. I think for me, it was the simple issue of not wanting to compromise, if that makes any sense. Though I was sort of easily in a position of power, if you would, to become popular, I just didn't wanna compromise and like and do the same things everyone else did.
As far as how it "feels" well of course it feels awesome to have everyone liking you. That's sort of a given. I don't know, as far as middle school and high school went after 7th grade, well, I had rumors about me and stuff, and I went through one of what I now know is like a "shut down" throughout it all, basically my life sucked. I didn't really have the choice to be popular then. I think before the rumors and general notniceness of live came about, though, it was just a simple choice for me of whether or not I wanted to "play along."
It's odd for me now, as like, I'm sorta "cooler" than most of my friends actually, I wear name brand clothes (I get them very cheap at Salvation Army), and it's weird, because it's like I'm "cool" now, but I don't have a "cool" social circle to go with my "coolness." And it's also weird, in that sort of my hobbies and stuff now alot are athletic, or working on cars, basically almost "anti-nerd" things, whereas my friends have graduated from anime nerds to D&D nerds. I no longer "fit in" with the "nerd" social groups, but I can't fit into the "cool" social groups either, or seemingly any social group.
Overall, I'd say don't feel sad about not being popular. If you value your independence, it's not a good state to be in.
http://www.paulgraham.com/nerds.html Very good article that reiterates my point.
Quote:
The main reason nerds are unpopular is that they have other things to think about. Their attention is drawn to books or the natural world, not fashions and parties. They're like someone trying to play soccer while balancing a glass of water on his head. Other players who can focus their whole attention on the game beat them effortlessly, and wonder why they seem so incapable.