Example 1: One loss becomes ten
A trader takes a normal, planned loss early in the session. Instead of accepting it, they feel a flash of anger and immediately re-enter, larger, without a setup, to get it back. That trade loses too, which deepens the feeling, and within an hour they have taken eight impulsive trades and lost many times the original amount. The first loss was fine and part of the business. The damage came entirely from the tilted reaction to it. A trader who stopped at their pre-set daily loss after the second or third trade would have had an ordinary down day instead of a disaster.
