Lessons : Happiness, get some.
Happiness is earned, it is not a gift, you cannot buy it and it is often fleeting when it does visit you. Happiness can be the result of doing something, extending yourself in ways you did not think possible, learning new skills, helping others, emptying your mind of all the distractions thereby allowing for moments of happiness to be experienced.
This lesson will greatly improve your lot in life, but it is directly proportional with how you apply it.
Happiness? Get some.