That's human nature. For many years, the system has tried to suppress human traits it deems unsuitable for social coexistence; I call it "control for passive slavery." You reminded me of a film called "Balance (2002)," where the system forced citizens to inject themselves with a serum to suppress feelings, a dystopian future where society is maintained in balance thanks to a drug that eliminates negative emotions.

>It probably stems from their mood

It is funny. I learned recently that emotions are only meant to last about 90 seconds, but it is because we hold onto the thoughts of events and don't let go that they turn into moods.