Theology Thursday--What the heck is joy?

All my life I've heard that Christians are supposed to be joyful.  I've even heard that joy isn't the same as happiness.  For the first time though I'm told at my church's ladies book study that joy is something the Holy Spirit does.  Now I have been taught that joy is a fruit of the Spirit, but anyone who reads Galations 5 can see it listed out plainly as one of the fruits of the Spirit, so that's an easy one.  A few times I've heard that joy is something that naturally comes out or shows clearly in a Christian.  See that's what I have a problem with.  I know how I feel a lot of the time and joy isn't it.  I'm not exactly sure what joy looks like.

I've seen people I know to be Christians walking around and they seem lighthearted and untouched by unusual tragedy.  Other Christians I've noticed seem to be dialed down a notch, but still have that something I can't identify, in common.  Then there are those whom I know that have incredible pain in their life that ebbs and flows like the tides.  I see the pain in their eyes, hear it in their voice, feel it in their writing and all the while, others say how strong they are, what a testimony they are, and all the platitudes that come with the comfort of others.  What they say is true, but the pain is still there.  Behind the brave smiles, and speech is pain; and the more other people tell you how strong you are and what a testimony the more constrained you become to hide the pain.  The days get better, sometimes you forget and then you remember again.  What makes the difference between daily agony, numbness, forced forgetfulness and joy?
There is an enormous gap between forced forgetfulness and joy.  How in the world does one get to joy?

So that brings me back to joy being a fruit of the Spirit and what that fruit looks like, especially in the lives of Christians who have had tragedy of various sorts.  Is joy possible with just the passage of time?  I say no.  Time doesn't heal squat; time gives you a chance to improve on your inner Spock. 
Another thing said at the ladies book study is that we don't have to act joyful.  Well that's a relief!  From what I understand the Spirit gives joy.  But I have several questions related to that: to whom, how, why, will He give it to me, and what do I have to do or be in order for the Spirit to give me joy?

A constant refrain I hear is that this is the middle of the story, this isn't all there is, God is still writing my story and He will finish it on time.  That's good to know and is actually a comfort; and for me there isn't much said that is intended to comfort which does in reality, it usually causes additional pain.
We are going through Ecclesiates and the book Joy at the End of the Tether by Douglas Wilson.  Perhaps I will have a better answer to what joy actually is and how it looks in Christians who have much pain by the time we finish this study.  At the same time my pastor just began preaching through Philipians, another joy topic.  Hopefully I'll learn something.  What I'm not looking forward to is hearing Phil 4:8 read and preached on.  That's a major trigger for me.  I think I'll stay home from church and bury my head on that day.