"I'm just grateful to be on this planet. I have no enemies that I know of. I'm just the guy who makes happy"

"I feel happy to terrify kids"

"I was married to Margaret Joan Howe in 1940. Although not a scientist herself she has contributed more to my work than anyone else by providing a peaceful and happy home"

"No man is happy who does not think himself so"

"Try to be happy in this present moment, and put not off being so to a time to come, as though that time should be of another make from this which has already come and is ours"

"Happy is the person who knows what to remember of the past, what to enjoy in the present, and what to plan for in the future"

"Happiness is the only good. The time to be happy is now. The place to be happy is here. The way to be happy is to make others so"

"A happy childhood has spoiled many a promising life"

"Great effort from great motives is the best definition of a happy life"

"He has no enemies, but is intensely disliked by his friends"

"Wonder if there is life on another planet? Let's suppose there is. Suppose further, that only one star in a trillion has a planet that could support life. If that were the case, then there would be at least 100 million planets that harbored life"