As some have noted already, JWs for the most part are *not* truly happy. They live in the shadow of happy and tell themselves they feel the sun, and no one has ever felt such sun. They have to say that and they have to believe that - it's justification of effort (our favorite!!!) again. How could they be ruining their lives if they're unhappy too!?!
Wow - holy cow - if average Joe witness knew how much better a shot of happiness they'd have living a normal life, their retention rate would be even worse than it is now.