Most of us like to think of ourselves as capable of logical thinking and making sensible choices, that is, of being rational.
But that’s not the way we are. As decision makers, we simplify, misunderstand, lack ability, miscalculate, forget, and make evaluations of alternatives that depend on seemingly irrelevant details about how a problem is framed. Rational? Yes, but only within certain limits; muddling through with a bag of tricks that don't serve us too badly.