How do you know you're happy?

If you're having a birthday and people wish you a happy day, is it incumbent upon you to be happy? If someone says: have a nice day, must you follow that advice?

You know you're happy if you're not crying, not cranky, not falling asleep at 9 PM on an otherwise normal workday. You know you're happy if you remember that your complaining gets you nowhere and that you can generate your own well-being by remaining in a state of relative ease in spite of the circumstances. You know you're happy if you can lose a gold earring and look for it and then resign yourself that it just may be your turn (again) to give up something treasured in order to remember that the day you die, you will give up all the treasures.

You know you're happy when you remember that it's good to be alive, in spite of the dirty dishes, the long overdue dental appointment, the very uncertain and frighteningly changing economy. You know you're happy when you remember you are not alone, no matter how shameful it sometimes feels to recall your own inadequacies.