Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning.
Albert Einstein

He who would learn to fly one day must first learn to stand and walk and run and climb and dance; one cannot fly into flying.
Friedrich Nietzsche

There is a magnet in your heart that will attract true friends. That magnet is unselfishness, thinking of others first; when you learn to live for others, they will live for you.
Paramahansa Yogananda

Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so.
Douglas Adams