Emotion and Action

I put up one phrase from my favorite homepage.
"Know that one's emotion follows his action." (Original is in Japanese.)
I've known this words from the beginning of July, but I didn't really understand it. But recently, when I felt a little sad, I automatically raised my head to be more cheerful. I actually felt lighter by doing that. Then I remembered this words and assented its meaning.
My emotion really followed my action. If this is the case in anytime, then I guess I should raise my head all the time.