I'm not considering this an issue, but asking more of advice for how to get along with it.
This is an issue, and I want advice, please?
I'm 17, and I really, just can't stand people in my own age group (14-18?). Especially guys. I cannot stand the thought of dating anybody under the age of 20. Even 20 feels a bit young to me. :/ I'm not sure what brought this preference of age to me, but it's been active for about 2 years now. I'm beginning to think it's a major problem with my personality or something. I've changed in a way that my friends haven't.
The friends I had 3 years ago, I got along with great, and we would do the same things, and laugh at the same stuff. Now, I can barely stand to have a conversation with them. We see/react to things completely different. I can barely relate to them.
I've noticed I do/feel the same way with the rest of my peers though, not just my friends. I actually became home-schooled to get away from people my age.
So, bottom-line : I cannot stand people my own age. It makes having friends, and dating difficult. So, what would you do? Any ideas?

It's not really a personality problem. There are many people who don't identify with people their own age. I've always gotten along better with adults than I have anyone else. I've just never been comfy around kids, teens, hell people in their early twenties sometimes throw me.
You're growing up, your tastes are changing, the way you see things and relate to things are changing. It is all part of the growing up process.
I admittedly am not the best person to ask for friend/dating advice (I'm a pretty serious loner, ha ha) but I just wanted to tell you that you aren't alone, and this isn't a personality problem.
Thanks for your input. I thought it was part of my personality because none of my old friends have changed like I have at all. I was afraid to call it ''growing up''. xD

just curious, have you hung-out with anyone from the age group you prefer?
I was this way, and am still this way, with many people. Except I've dubbed it a maturity/personality thing (with other people, that is). For instance.. I hate the majority of the people I went to high school with, except very few who don't act like they're 12.
I have, yes. Most of my friends have older siblings, and I always wind up gravitating towards them. I'm an only child though, and my mom used to drag me around to bars, so I hung out most of the time with old drunk people when I was younger, which I thought might play a role.

mmkay. just curious since i didn't see i mentioned in the op.
that sounds like it played a role, since i'm in the same situation and when i was younger i hung out with my mom's friends as well.
since you mentioned older siblings, have you ever tried to get to be good friends with them? that could help you befriend more people in that age range.
Um, I guess you could say I've tried. I use to go to my friend's house all the time for her older brother and sister, and wound up being better friends with them. My friend wound up with the thought I was using her to befriend them (I guess I was at the time, didn't realize it though..).

I don't see why that's weird at all. I was the same way and started to realize it by the time I was 13. For example, when we went out to eat with a big church group, I would demand to sit at the "adult table" and talk about the serious stuff with the adults, rather than with the kids my own age. Luckily, no one minded at all. At least, they didn't ever say so where I could hear it.
Anyway, I'm 24 now, and it seems like most of my friends my age have caught up to me now. There are some that are a little 'behind', you could say. But for the most part, they are all very mature and on (or around) the same page as me.
And besides, most girls end up marrying guys who are older than them.
BUT, that all being said, I think it depends on the person, really. I've dated guys in varying ages older than me, and I finally married my husband who is 3 years older. But when I was a senior in high school, I dated a freshman in high school. We stayed together during my freshman year at college. The only thing that made it work for as long as it did was the fact that he was waaaay more mature than all the other guys I knew at the time. He was a foreign student whose wealthy father wanted him to have the "American advantage", but in his town, boys were doing much more than just attending high school at age 15.
It's relieving to know there are other people like this, but, when you were my age, did you ever seriously want to stop attending school with people your own age for the same reason? :/ Just curious~

Ohhhh, most definitely! When I was a freshman, I found out that the local university here helps students graduate sooner by correspondence courses in combination with their regular courses. A distant (older) friend of mine had recently graduated that way, from another school. I went to a very small, private, Christian school, so I didn't think it would be a problem. I researched the whole thing, pre-applied and got accepted, and produced an entire packet of information for my counselor and principal to sign off on it. I brought my parents with me (who supported it completely), and we gave them a little presentation. They rejected it, for whatever reason--I'm still not sure, to this day.
By then, it was a) go to public school where I knew they would let me do it, for sure, and deal with thousands of kids my own age, or b) stay in the private school where there were only 15 kids in the freshman class, period. Needless to say, I stayed. My mother refused to home school.
Oh. Well thank you again. <3 I'm actually trying to graduate early myself, blindly though. I suppose I should get around to researching it like yourself.

Same here, the guys in my grade act so stupid -__-" They are always carrying on about something,throwing things at the bus driver, lighting things on fire ON THE BUS, throwing stuff at cars going by...until the driver got out that is, swearing etc...
They do worse things but I'm not going to keep going on xP I'm not going to be with anyone till I'm older, the guy I like is immature :/