Sometimes people are mean when they don't understand you.
Some are mean with others in order to gain or mantain acceptance in a peer group.
I agree that others do it because they can, and get a thrill by doing that even if they deny it. (seen that online, out of boredom)
Some are mean with people that are different from them.
I see that being mean and getting a thrill by it and not caring, is a stupid and selfish thing, while some people are mean sometimes based on the emotional state at a certain time, which they later regret.
I can't stand a little bit of a mean action from people IRL, even if it is small, due to social anxiety I guess, and insecurities, although some jokes people have made sometimes I have taken them literally.
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?Everything is perfect in the universe - even your desire to improve it.?