People, usually tend to give more importance to the negative side of things, always leaving out or giving less importance to positive things.
The example shown is very graphic, in a loving relationship we always see the two parts of the other person, positive and negative, but we always give more importance to the negative part, depriving us of living nicer situations and preventing us from doing Decisions, which are not always correct.
We must develop our mind and get rid of those complexes that deprive us of living better experiences throughout life.