Healing is often a state of mind. Have you ever noticed how after laughing you just feel good and gleeful? That's you're whole body responding in a positive way. On the other hand, when you're sad, your whole body sags, you may cry, you feel depressed. Stop that! Sit and smile. Practice that. You don't even have to think good thoughts. Just smile.
When you laugh, you physically make yourself better. So open up and say "haaa".
More on this another day.
