You are an irrational person. Yes, you.
That’s not an insult. If you can read this, you’re a human being — and that makes you irrational. In fact, I believe — in all seriousness — that every human being is just a little bit insane. Some form of insanity is a universal “birth defect” among us.
One of the biggest mistakes we make in life is assuming we’re rational. What’s worse, we notice that other people seem irrational and stupid, but almost all of us believe we’re the exception. My way of looking at the world is right and rational. Your way is wrong and irrational. (You probably have evil motives, too.)
You are the hero of your own story. In your own mind, you believe you’re making rational and smart and sane decisions. You believe you have good motives, at least within the context of however you’ve justified your own actions.
I do exactly the same thing. And our mutual blindness about this whole charade leaves us with warped perceptions of the world around us — and of each other.

We have no choice but to trust even in face of betrayal and hurt
In praise of the weirdos who most people don’t really seem to like
For good or bad, we default back to what feels most familiar to us
Heinlein: It’s not just ‘bad luck’ when creative minority is hated
To become extraordinary people, we can’t behave in ordinary ways
Loss of cultural consensus means violent conflict in decades ahead
If you repress feelings long enough, depression attacks without warning
Does mainstream schooling model bring out the worst in teen-agers?