The groups of people that made you feel left out when you were young don’t have the power to do that to you as an adult. Adulthood means taking responsibility for your own experience and choosing the terms of your participation in causes and groups. When you get that “left out” feeling, it’s worth asking if its genesis is truly external–a group of people and their behavior toward you–or if it isn’t internal, a holdover from adolescence that you’ve outgrown.
Maturity means enlisting people in our causes and our communities more and seeking to be accepted into others’ less.