Rationalizing an event may help individuals maintain self-respect or avoid guilt over something they have done wrong. In many cases, rationalization is not harmful, but continuous self-deception, when a person consistently makes excuses for destructive behavior, can become dangerous.

Why you should not rationalize when making decisions?

Again, rationalising our decisions boils down to engaging emotion during the decision-making process. ... Emotionally-based decisions do not facilitate this the way logic does, because a logical decision is one based on evaluating inferential relationships among various objective justifications.

Why do we rationalize our mistakes?

Rationalization is actually a defense mechanism that allows you to justify bad behavior or feelings. It's a way to distort facts to make things look better than they do – to convince others and yourself that your motives and actions are good, not bad.