Try not to let selective memory mess ya up; a majority of your kindness is likely forgotten (saying thank you, watching someone’s bag while they are away five minutes, etc) until you get the one time it backfires. Rare events, especially negative ones, have high salience.

Cruel impulsives, on the other hand, you tend to remember when you were driven to a rage or when you shouted at someone you love. Impulses you should regret but do happen to normative people.

Unless you’re a terrible person, anyway, then these are reversed. Common cruelty and rare kindness aren’t default human behavior because it’s counter to tribal survival and evolution would just kill you off. That behavior usually the result of something like a toxic culture or upbringing, and very occasionally psychosis.