I went to Oxford and even though everyone else there seemed pretty smart too I still didn't really make friends or develop meaningful relationships. It took me many years of basically just being isolated from others before I learned about the concept of "attachment styles" and started working on "Earned Secure Attachment" which basically means you build your own sense of attachment as an adult to correct the problematic aspects of your attachment style from childhood. It's unfortunate that kids who don't really "fit in" and end up being fairly isolated socially even though they are intelligent don't have a way of finding out how to solve that problem and that people just go around encouraging kids to be more socially active and suchlike. Even if you are socially active, you are probably not going to be able to form successful adult relationships without help if you already fall into the category that the OP is referencing.