Once you actually take human nature into account (especially, the the things that cause us to feel happiness, pride, regret, empathy), then most seemingly-irrational human behavior actually turns out to be quite rational.

Conscious thought processes are often deficient in comparison to subconscious ones, both in terms of speed and in terms of amount of information they can integrate together to make decisions.

From 1 and 2 it follows that most attempts at trying to consciously improve 'rational' behavior will end up falling short or backfiring.