Dear Thelma: Why do my friends treat me like dirt?

Friendship is a matter that surely has been long debated and agonised over, yet here I am, knocking on the door for answers once again.

I am a highly introverted person with the tendency to close off my emotions to the outside world, resulting in numerous accusations of being aloof, arrogant and being an emotionless robot without a “life”. The few friends I have made were all in the same class or school as I was.