People are terrified of other people or difficult projects because they tell themselves that they could fail or be rejected. Failure can lead to sorrow, regret, frustration and annoyance - all healthy, negative feelings without which people couldn't exist. But then they add, "I absolutely must succeed and must be loved by significant persons, and if I don't, it's terrible and I'm no good." Those are irrational beliefs. As long as people keep them, they'll be terrified of life and will put themselves down when they get rejected.