The following pithy wisdom is found on the wall of Shishu Bhavan, a children's home run by Mother Teresa's Missionaries of Charity in Calcutta, India.
People are unreasonable, illogical and self-centered.
If you do good, people will accuse you of selfish, ulterior motives. If you are successful, you will win false friends and true enemies. The good you do will be forgotten tomorrow. What you spent years building may be destroyed.