Fear. Could be fear of rejection, fear of what others will think of that person. Fear of socializing.<br />
The reason why all of us don't do something is always because of a fear we have. Once you get over your fears you can do anything and everything you want, without holding back.
What about if you have just had some bad experiences and you totally just like being a loner. I feel that about myself be I can also be a social butterfly . I was an only child and grew up with adults in the home older (grandparents) so I had to not only grow up faster, but also entertain myself too. I enjoy being alone. But you have to know the difference between lonely and being alone.....
I don't know...I have a "friend" who is doing that right now, and he is making me crazy.<br />
I think that must be a very lonely way to be.... you are so young. I hope it will change for you. You can trust people and at least give them a chance before you decide to pull away so far.
That's your mind feeling the opposite of what you are supposed to be feeling when someone reaches out to you. It's happened to me I got help with a very small dose of abilify. Abilify is your friendly neighborhood spiderman.