You need a little bit of insanity to do great things.
You can't live a perfect day until you do something for someone who will never be able to repay you.
When obstacles arise, you change your direction to reach your goal; you do not change your decision to get there.
The expectations of life depend upon diligence; the mechanic that would perfect his work must first sharpen his tools.
Repetition of the same thought or physical action develops into a habit which, repeated frequently enough, becomes an automatic reflex.
My optimism wears heavy boots and is loud.
People don't realize how a man's whole life can be changed by one book.
I don't think necessity is the mother of invention. Invention ... arises directly from idleness, possibly also from laziness. To save oneself trouble.
You have to dream before your dreams can come true.
I don't know who my grandfather was; I'm much more concerned to know what his grandson will be.
Improvement makes strait roads, but the crooked roads without Improvement, are roads of Genius.
The deeds you do may be the only sermon some persons will hear today.
Gratitude is an illness suffered by dogs.
We are citizens of the world. The tragedy of our times is that we do not know this.
You must find the place inside yourself where nothing is impossible.
The man with no imagination has no wings.
It's the little details that are vital. Little things make big things happen.
This is one small step for a man, one giant leap for mankind.
If you can accept losing, you can't win.
We should not give up and we should not allow the problem to defeat us.
To give pleasure to a single heart by a single act is better than a thousand heads bowing in prayer.