Why does one bad comment stick longer than ten good ones?
Ten people praise your work and one criticizes it - guess which voice you hear all night.
Bad events hit harder than equally good ones. A loss, an insult, or a piece of negative feedback grabs more attention, stirs more emotion, and lingers far longer in memory than a positive event of the same size. Your brain treats bad as urgent and good as optional.
You get 50 likes on a post and one rude comment, and it is the rude comment you replay on the way home.
Bad outweighs good, so it takes several positives to balance out a single negative of the same size.
Knowing bad weighs more lets you correct for it - reread the praise, not just the one harsh line, before deciding how your day actually went.
Negativity bias = bad news shouts, good news whispers.
Learn the idea and practice English at the same time.