Yes... happiness is a myth...
Seriously though, some people hit the jackpot and some do not...
I don't believe in heaven or anything, but if we managed to keep ourselves alive for a little longer I do believe we'll be able to keep ourselves in a near constant state of happiness 24/7 through technological breakthroughs with the mind, though it'll probably be a few generations out of our reach lol. We can learn how to enjoy sorrow and sadness though, and I have a feeling people in the future won't be walking around in a happy daze all the time.