What lessons have you learnt by observing a toddler or a small kid in leading a happy life?

Your question brought a smile to my face :) The first thing I have learned is to take joy in the smallest and most insignificant looking things in life. It's such an amazing feeling to be happy with simple and uncomplicated joys. I've of course also learned the virtue of patience, of questioning and having an open mind, of trying out new things even if I know I may not succeed at first, and of loving unconditionally and showing my emotions to those who are special to me :)