He who knows all the answers has not been asked all the questions.--------------------------------------------------------Gender-inclusive, paraphrased version: Those who know all the answers have not been asked all the questions.
A man is great not because he hasn't failed; a man is great because failure hasn't stopped him. ------------------------------------------------Gender-inclusive version: A person is great not because she or he hasn't failed; a person is great because failure hasn't...
The man who asks a question is a fool for a minute; the man who does not ask is a fool for life. -------------------------------------------------Gender-inclusive version: The person who asks a question is a fool for a minute; the person who does not ask is a fool for...
Before you embark on a journey of revenge, dig two graves.
If you hate a person, then you're defeated by them.