Just don't be that introvert who doesn't initiate conversation or contact than the gets in a huff because no one invites you to anything or talks to you. You can make the choice, but as with all choices, you have to learn to live with your choices.

I used to be much more introverted than I am now. I'm still essentially an introvert, but I've become more comfortable conversing with people I don't know very well. It took getting involved in some activities that put me in contact with relative strangers on a regular basis. These are large-group organizations where I am moved around and sitting to different people almost every time we meet. Teaches the art of small talk really fast . . . and some of that initial small talk has developed those relationships into nice friendships over time.