When a person lives a life so privileged that their bad decisions bear them little negative consequence, they start to believe all their opinions are good ones.
a lot of folks have said this approximate sentiment in a more elegant fashion,
but I do definitely think that everyone needs someone in their life - a close friend, a therapist, some kind of counselor - who is willing and able to take them aside from time to time and say "hey you're slinging bullshit, cut that the fuck out"