> I would imagine if someone at the office started claiming your work at your own you would probably experience something rather analogous to anger.
I'd be more incredulous than angry. The vast majority of my work is well tracked in VCS and easily shown to be my work - such claims of... what, insecurity? Greed? Fear? Are typically self-defeating, easily disproven, transparent, and rather pitiable. They merely invite closer scrutiny and undermine themselves, the value of their word, and destroy the trust people have in them. They're probably not even smart enough to claim just my work as their own, but probably that of several people. It's worth speaking up to try and nip the problem in the bud, but everyone probably already knows they're an untrustworthy braggart.
They're not hurting me, they're hurting themselves, and they're often too trapped in their maladaptive coping patterns from previous toxic relationships and environments where such actions were perhaps not only effective - but perhaps even necessary to succeed within those environments - to stop.
Maybe they'll recover.
Maybe they'll get fired.
Maybe they'll be able to get stuff done while being rendered harmless. Yes bob, good job doing the entire project A while simultaniously fighting off both godzilla and mothra (eyeroll). By the way, you can do project B all by yourself, right? Since you're so awesome? No no - we're sure you can handle it. I wouldn't want to step on your toes.
Maybe I'll get a better job.
> It might also be your life situation is such that people don't really try to take advantage of you or mistreat you very often.
You can control that life situation a lot.
If someone consistently mistreats you, remove them from your life, because you can do better than that. Repeat to taste.
If your "customer is always right" job tells you to smile in response to verbal abuse, find another that lets you ban them from the store instead. Where anger might focus on "getting even", instead focus on "preventing this from becoming a pattern."
If you can't quit your job yet, discount their verbal lashing out as the angry adult temper tantrum that it is. Discount their tirades as the worthless ventings that they are - targeted at the world, not you specifically - and pity them for their failure to become a worthwhile adult. Or perhaps they're screaming because their dog just died, and they don't know how to process that. Perhaps they just learned they have cancer. Perhaps they don't know about their brain tumor yet. Perhaps they fear. That doesn't justify their frothing spittle, but one can pity and sympathise with a person unable to properly express their emotions in a constructive and healthy way - because we've all been there, and so many of us are fortunate enough to not live there like some of these poor bastards do.
Which isn't to say it's never worthwhile to get properly angry, but often the biggest victim of the angry and the cruel is themselves. They push away friends, family, coworkers, opportunities, and kindness - and are often left with only mindless hedonism and misery themselves. No wonder they're such a miserable prick.
I also realize much of this is easier said than done.