"I think my capacity to change has given me tremendous happiness, because who I am today I am completely content to be"

"The best preparation for good work tomorrow is to do good work today"

"The man who makes everything that leads to happiness depends upon himself, and not upon other men, has adopted the very best plan for living happily. This is the man of moderation, the man of manly character and of wisdom"

"Happiness is not a state to arrive at, but a manner of traveling"

"Action may not always bring happiness; but there is no happiness without action"

"Happiness is not a reward - it is a consequence. Suffering is not a punishment - it is a result"

"Knowledge of what is possible is the beginning of happiness"

"In thinking about nanotechnology today, what's most important is understanding where it leads, what nanotechnology will look like after we reach the assembler breakthrough"

"Happiness depends more on the inward disposition of mind than on outward circumstances"

"It is not true that suffering ennobles the character; happiness does that sometimes, but suffering for the most part, makes men petty and vindictive"

"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"