“Keep on going and the chances are you will stumble on something, perhaps when you are least expecting it. I have never heard of anyone stumbling on something sitting down.”

“Don't give up. Keep going. there is always a chance that you stumble onto something terrific. I have never heard of anyone stumbling over anything while he was sitting down”

“The Wright brothers flew right through the smoke screen of impossibility.”

“It doesn't matter if you try and try and try again, and fail. It does matter if you try and fail, and fail to try again.”

“We should all be concerned about [the future] because we will have to spend the rest of our lives there!”

“when you stumble, keep faith. And when you're knocked down, get right back up and never listen to anyone who says you can't or shouldn't go on.”

“An inventor fails 999 times, and if he succeeds once, he's in. He treats his failures simply as practice shots.”