What has stuck out to me in reading Lewis' Surprised by Joy is this observation he makes on Enjoyment and Contemplation. He says that when we enjoy something, an "object", we are focused primarily on the object -- we are almost lost in the object. But when we try to contemplate or keep up that joy and enjoyment (and thereby focus on the enjoyment or joy itself, instead of the object) we will lose both the object and the joy. So, in order to enjoy an object (say, a person, meal, party, etc.) we must be focused on the object itself, not attempting to get the joy. He puts it (much better) like this:
"...one essential property of love, hate, fear, hope, or desire was attention to their object. To cease thinking about or attending to the woman is, so far, to cease loving; to cease thinking about or attending to the dreaded thing is, so far, to cease being afraid."
He continues this idea further:
"In other words the enjoyment and the contemplation of our inner activities are incompatible. You cannot hope and also think about hoping at the same moment; for in hope we look to hope's object and we interrupt this by (so to speak) turning around to look at the hope itself."
This distinction becomes important when we look at how we go about having hope, or joy, or these other desires. I find so often that we (as Americans, and as Christians) always seem to want to have "hope" or "joy" or "love" or "faith", but never recognize that each needs to take on object, and a proper one at that. Without the object of hope, hope has no meaning. Likewise, without the object of joy, joy has no meaning (this is what Lewis concludes in his lifelong search for joy -- he realized it wasn't what he was searching for, he was searching for joy's object). We want joy so much, but we cannot have it without the proper object. And to our dismay, we pick objects that are temporal and fading, and thus our joy becomes temporal and fading with the object (e.g. money, health, boyfriend/girlfriend/spouse, children, etc.) Or we become so worried about getting joy that we forget that the only way to obtain it is to focus on something else (a sort of lose-your-life-to-gain-it-Matthew-10:39-thing). But this distinction can save us a world of trouble if we recognize the difference between our joy (or hope, desire, etc.) and the object that brings our joy.
Lewis further shows how this distinction can work both for us, and against us:
"The surest means of disarming an anger or a lust was to turn your attention from the girl or the insult and start examining the passion itself. The surest way of spoiling a pleasure was to start examining your satisfaction."
I find this very intriguing. When in sin, the more I focus on the object of my desire the more it fuels the sin, but when I stop and look at the desire and the sin itself, I typically realize how absurd and ridiculous my sin is, and forget about and lose sight of its object. But on the flip side, when I try so much to obtain pleasure or joy without the object, I cannot find it at all. This, as I said before, is what Lewis' conclusion is at the end of his book Surprised by Joy: he spent his whole life looking for "Joy" and trying to retain it constantly, but he finally realized that what he really wanted was the object of "Joy", not joy itself. And the proper object of joy which he found is God (or, as he puts it, God found him).
So the funny thing about life (and particularly, joy) is this: in order to get joy you have to forget about it and focus on something else (namely, God). But the saddest thing about life is that we (I mean, Christians) too often don't get this right. In fact, we do the opposite all of the time. We want the joy/hope/etc. and so we use God so that we can have joy, but then we forget about God entirely. We get God for the things he gives us, but then we revel in the things He gives us over God Himself! Those things are good, and He does give us them, but why would we rather having them over having God?!? We focus too much on the thing we want, and we lose the object so much, we lose God. When we focus on God we get the joy as well, but that's not as important as God. But when we focus on the joy itself, we lose both the joy and God. What a travesty. And what's worse, I see it in my life too often.
It's like the fruit of the Spirit in Galatians 5: we all want the fruit, we all want love, joy, peace, patience, etc., but we all forget that it's all the fruit (singular!) of the Spirit! If you want the fruit you need the root (to borrow a Reformed expression). To get all that good character stuff, don't go after it -- go after God! Then you'll get it as a product of the object.
So we need to rethink what we really want and how to get it. I would contend that the ultimate way to gain joy/hope/peace/etc. is to "gain Christ", and often the way we do that is by losing everything else (c.f. Paul's statements in Philippians 3:9-11; or Jesus's Matthew 10:38-39). But if we realize truly what God is (i.e. eternal life!), then losing everything for it is really not much of a loss. And when we focus on God as our object, the result is that we get all of these other things (fruit of the Spirit, heaven, life, etc.).
Hopefully that makes sense to someone. But if it doesn't, that's reason enough to go and read Lewis for yourself: he's much better at explaining these things than I am.