Even if you're unhappy just pretend that you're happy. Eventually your smile will be contagious to yourself. I had to learn that. I used to think 'I'm being fake ' but you know what? Better to be fake and happy than real and miserable.

A lot of people over time have had this kind of pattern in their relationship with Bill Clinton. You first meet him and you're overwhelmed by his talent. He's so energetic and articulate and full of ideas and he calls himself a congenital optimist and that optimism is contagious.

No company is preferable to bad. We are more apt to catch the vices of others than virtues as disease is far more contagious than health.

I think the key to happiness is allowing ourselves to not feel bad or guilty for feeling it and letting it be contagious. And to not be dependent on other people to create your own happiness.

Remember that happiness is as contagious as gloom. It should be the first duty of those who are happy to let others know of their gladness.

Nothing is so contagious as example and we never do any great good or evil which does not produce its like.

Freedom is the most contagious virus known to man.

Freedom is contagious. That's why despots fear it so much.

There is no passion so contagious as that of fear.

You may not always have a comfortable life and you will not always be able to solve all of the world's problems at once but don't ever underestimate the importance you can have because history has shown us that courage can be contagious and hope can take on a life of its own.