The next time you think about rejecting someone, try loving them instead.
You'll find it is more difficult than you might imagine. If you usually pride yourself on loving many people, you may be caught by the sudden contradiction of your behavior, when you find it hard to love someone when it does not come naturally.
Even after ten years reading books and working on myself, I still
catch myself subtly making separating distinctions and judgments that
offer me a rationalization to close off my heart. Only in the last year
and a half can I say that I have loved others and acted responsibly
towards all the people I've gotten involved with, even throughout
changes in the relationship. Handling a change in the relationship form
(what others might sometimes call a "break up") is probably the most
difficult time to maintain ones mindfulness and compassion.
And it is difficult, in this case, because loving this person would not be based on our own selfish desires. You see, loving someone is easy when it also fulfills our own selfish desires. That is not really true love. Loving someone in this way is a form of self-deception. We say, "I love you," but we only say it because they make us feel good. When we try to love someone we may want to reject, we realize that true love isn't selfish. It isn't about us, and how they make us feel. True love is about showing kindness towards another despite how they make us feel - good or bad. If they are fundamentally a good, decent person, we have no excuse not to love them, other than for the want to fulfill our own desires.
Now, maybe you're not interested in loving people in this way. If that is the case, please stop reading. Go on and drink your beers, party it up like nothing else matters, and keep pursuing your own little needs. This wasn't meant for people with that kind of attitude. If you are still reading this, it's because you have a desire to challenge yourself, to become a better person - to love more, to be kinder, to be less judgmental, to be less selfish and more other-oriented.
If you want to grow, evolve - then choose to love the next person you subconsciously or consciously want to judge and reject.
When our view of the other person is not filtered through our own desires, we realize they are just another person like ourselves. Equally deserving respect and kindness, just as we do, so long as we are not a jackass. If we act like a jackass towards our friends, towards our ex-partners, or to people we don't know, then maybe we don't deserve much extra consideration. But at its essence, we were all an innocent five-year-old child once, and we all fundamentally deserve respect and kindness on a basic level.
If you cannot do this, then all your words about how "I love lots of people" will ring hallow. It's easy for our minds to congratulate ourselves with such narratives, when the behavior in actual practice falls short of the hype. The mind can easily create blind spots that hide our own contradictions, if we're not mindful of what's going on up there in our heads.
A true measurement of a person's character can not be derived from how they threat those they like, but how they treat those they have written off. The act of writing someone off, in a way that lacks love and kindness, is proof enough, that that person has a lot of growing up to do.