Not quite as simple as that, it's an innate part of human psychology that people will stick to something once they have made a choice(actually think it's an innate survival trait gone awry, something evolved from the survival advantage from finishing/carrying through a task) even in the face of conclusive proof that it will ruin/destroy them

There was a study done on this with the stock/commodities market as the studied environment and they found that once people had made a decision you could show them irrefutable proof that they would loose all their money and only a small percentage would act on the new information or do anything other than cling to their decision.

Unfortunately this also applies to reasoned intelligent people, geniuses even. Someone can be the most intelligent, reasoned, analytical and smart person you have ever met, and still be an absolute intransigent moron about one single thing.......