There is a certain degree of satisfaction in having the courage to admit one's errors. It not only clears up the air of guilt and defensiveness, but often helps solve the problem created by the error.
Dale Carnegie - Courage - Solutions - Problems - Mistakes

Learning is an active process. We learn by doing.. Only knowledge that is used sticks in your mind.
Dale Carnegie - Learning - Knowledge

The resentment that criticism engenders can demoralize employees, family members and friends, and still not correct the situation that has been condemned.
Dale Carnegie - Criticism - Employee - Family

Any fool can criticize, condemn & complain.. and most fools do.
Dale Carnegie - Criticism

Even in such technical lines as engineering, about 15% of one's financial success is due one's technical knowledge and about 85% is due to skill in human engineering, to personality and the ability to lead people.
Dale Carnegie - Skill - Technology - People - Knowledge - Success

Dealing with people is probably the biggest problem you face, especially if you are in business. Yes, and that is also true if you are a housewife, architect or engineer.
Dale Carnegie - People - Business - Customers - Problems