Currently I had to think about something evil I did. Long story. I go to a college self-help group. We were not sure whether we open the group to non college students. Now we changed the policy and we are inclusive.
I was in a different group for mentally ill people. And advertized the college self-help group. But I realized there was such an annoying womanizer. He flirted all the time with women (only the one's who were attractive by societal standards). He always split the group to be alone with them.
I was sort of annoyed and a little bit jealous. So I just prerended the college group is only open for college students. I basically gatekeep the group. Spending time with women improved my skills when it comes to dating.