You know how annoying it is when someone brags about themselves? It is hard to listen to; right? Those of us who are aware, try to practice not bragging.
If one doesn’t like bragging, they should be just as uncomfortable with self derogatory remarks. Self put-downs are the flip side of bragging. They both indicate an imbalance in the ego. If one doesn’t like to brag, they should also not like to diminish themselves with unflattering comments.
When those two distinctions are blurred, both extremes will be met with equal disdain. Balance can be reinstated.