For this I would have to say shyness. Although shyness isn't normally classified as a fear I believe that at least in my case it was a fear. A fear of the unknown, of taking risks that would endanger people’s opinions of me. I used to be scared of going to buy things at the shops and talking to the checkout operator. I don't know why it is completely irrational and I personally now am embarrassed at the stupidity of this behaviour. Now I will just start talking randomly to whomever is sitting next to me at school regardless of whether they are a friend or not. It is so much nicer to not be confined to such a small world without all the opportunities and insight that can be gained through talking to other people.