You can appear to be really happy on the outside when you’re actually miserable inside. The key to being genuinely happy in life is to be fulfilled and balanced on the inside. It means living your life according to your natural talents and abilities and consistently thinking and behaving in positive ways. Worry less about what you look like to others and more about how meaningful your life is.
Tips and advice on how to be happy in life by Guy Farmer, How to Be Happy blog.