On Stupidity

Why is it that some people are so terminally stupid? So much so that they ignore something hoping that it will go away? So much so that they will alter their daily routine and most likely contort their thought patterns? Do they not realize that this makes things worse?

Is it truly worth so much effort not to have to say the words "I'm sorry?" Why not just save the trouble, time and energy and get it over with? Eventually, one will have to apologize, and hurts accrue interest at 100% rate that's compounded daily.