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 today will be forgotten tomorrow. Honesty and frankness make you vulnerable.
People favor underdogs but follow only top dogs.
What you spend years building may be destroyed overnight. People really need help but may attack you if you help them. Give the world the best you have, and you'll get kicked in the teeth.