Recently, when I was talking with my (non-Catholic) wife and daughter, I used the phrase "offering it up" when referring to some sort of discomfort. I think they both thought I was a little nuts, so I thought I'd write a little about the wisdom of the attitude that the phrase expresses.
When I was a boy in Catholic school in Southern California, and we kids were, for example, miserable and complaining in our non-air-conditioned classroom on some torrid September afternoon, the nuns (who, wearing the old black habits, must have been far more uncomfortable than we were) would tell us to take it patiently, and "offer it up." The idea was to take the suffering you were experiencing, large or small, and ask God to accept it along with the sufferings of Christ in recompense for sin. Since we all knew we had sins, and there was plenty of it elsewhere in the world, it made sense, and always quieted things down for a while.
I think there was a great deal of wisdom in that little practice. The problem of suffering is one that has troubled many great thinkers, and disturbs all of us when something bad happens to us, especially if we think we didn't deserve it. And one of the most desolate feelings a human being can have is that his suffering has no meaning. The fact that kids' sufferings are often small by adult standards doesn't mean that they aren't acutely felt. So "offering it up" gave us a way to attach a great -- and real -- significance to whatever we were going through; it allowed us to unite our little hurts, especially the undeserved ones, with the far greater hurts suffered by Him whose suffering was utterly undeserved, and participate a little in the great work of our own redemption.
To those of you who may be saying, "Oh, that evil, guilt-inducing Catholic Church! What kind of sins could you kids possibly have done that could merit feeling spiritually guilty for?", I would ask: do you really remember your own middle-school days? Do you remember the spite and cruelty that made school life a little hell sometimes? Seems to me those were plenty nasty enough to merit a little guilt -- and to motivate us to expiate a bit of it with a little patient "offering up" of the misery of those 100-degree dog days, late in summer.