We don’t fully understand why we make decisions. In fact, decisions are made in our brains before we become aware of having decided.
So when we outline a logical explanation for our decision, we’re making it up after the fact.
It’s not necessarily all false or wrong, though it might be. But it’s definitely incomplete, and it might entirely leave out the predominant factor in our decision.
When we explain our reasoning, we’re telling a story to ourselves and others. Stories are great! We can learn from them. But we know they’re not true.