I don't worry about happiness. If I was permanently sad, for no good reason, what would I be when something bad happened? Extra sad? A realy, really sad bastard? Possibly the latter.
So, in the interests of maintaining a positive mental attitude, which is essentially how you survive in this world without turning into a quivering emotional jelly, I think we should take joy in mildly amusing stuff, no matter how childish or trivial.
To this end, I bring you a thing from my little boy's letter board:
Heh - that totally says 'dog egg'.
Obviously, sanity can only be maintained if we ignore reality, because that shit will just depress the seratonin right out of you, but I'm fairly confident we've all got the wherewithal to do that.
If you find yourself slipping into some kind of reality-induced melancholy, try this link.
Hope it helps.