"Rational" doesn't mean correct, it only means "logical". For example, a neural net for discriminating between cats and dogs is, in general irrational - and yet it does so better than anything based on pure symbolic logic.

Humans are inherently irrational. We try to emulate rational behavior because a logic gives us certainity and lets us feel secure about the outcomes, but we are physically incapable of acting in a logical way for several reasons. We don't have enough data to make a fully justified decision in every situation, and if we did, it would still cost too much energy for our meat brains to actually compute those decisions.

So we approximate rational behavior, making statistical guesses. With enough data (experience), those guesses are good. Other times, your guesses are bad. Sometimes you have barely any data at all and are forced to choose between several options that all carry risks, so you go with your instinct. Is it rational? No, but it might have been the least bad choice, as in real-world, real-time situations, failure to make any choice whatsoever is itself a choice, and usually a bad one.

ps: I come from the AI field so I have no idea how any of this relates to economics.