What motivates someone to choose a life fueled by caffeine and all-nighters just to help others live better?

What's the best way to react when someone is trying to manipulate others against you, especially with outrageous lies?
How can changing my focus from my troubles to a new understanding of life make a real difference?
How do you stop yourself from diagnosing your friends and family when you are off the clock?
What are some surprising things people have regained even after thinking they were lost due to aging?