Happiness is really such a broad term. One can be happy, no matter what is going on in some circumstances. Despite suffering and pain, they can still keep on keepin on, as long as they feel they are doing the right thing. It empowers them. I know. I've been there.
When I was a JW, I was seldom what you would call "happy". But I continued believing that this was my sacrifice in life. I think I also had other issues going on, such as a dysfunctional family, low self-esteem, and depression even when I was young. The JW experience magified my insecurities and held me captive for so much of my life--well until I was about 54 before I made a very determined effort to get rid of all that baggage that was still a part of me, even though I had walked away some twenty years prior. That is rather amazing to me, as I type this out.....so much of my life lived in fear of laying everything out and disecting it
I would say now that I am a joyful person and that I experience happiness for all the right reasons, so much more than ever before in my life. Unbelievable that I denied myself that right for so long. I cannot blame anyone but myself.