Sure enough, the answer came when I read Fr. Martin Fox's homily for Mass today. In it, he says:
Jesus healed tons of people—where were they on Good Friday? How many, today, look at the Cross, and say,“hey, thanks Jesus!” and they go their way? It’s not easy to look at the Cross, and know you’re not ready to respond. (By the way: that’s why many mock the Cross, why they destroy the Cross, why they don’t want it around.) At the center of the Mass, here is how fully He shows us his Cross:It becomes real, right here, on the altar—his suffering and death, happens right here!
We don't want to hear the message of the Cross even after we've been professing it with our lips and experiencing it, within and outside Mass, all our lives. We don't want to be reminded that there are no shortcuts to real happiness, i.e. to the eternal life to which we are called by the Gospel, and into which we are initiated in baptism. The only path is death: not merely physical death, but the death of the "old Adam," the self corrupted by original sin. Accomplished in principle for us by Jesus, that spiritual death is the work of a lifetime for us. Physical death is both the natural end of that old Adam and the outward sign of what we must freely undergo in our souls if we are to be reborn as the selves God created us to be. As I have learned by reading exorcism transcripts from Martin and others, that's why Satan and his wretched kingdom "mock the Cross, destroy the Cross, don't want it around" (to use Fr. Fox's phrases). Even as a symbol, a physical object, the Cross challenges that self-will which led to Satan's rebellion and irremediable downfall in illo tempore, which lives on in us as an effect of original sin, and which will lead us straight into the infernal Kingdom if we don't cooperate with God in its crucifixion.
Now I know why I often have such a hard time being grateful to God at the Eucharist. Eucharistia is Greek for 'thanksgiving', but I don't want to thank God for the Cross. In fact, most of the time I feel that my life....well, sucks. Oh sure, I'm happy to thank Jesus for undergoing horrific torture and execution for me; but I don't want to avail myself of the opportunity he thereby gained for us, which is embrace the Cross as our own in daily life by the power of his Cross. I know I have to be crucified in my own little yet all-too-painful ways, but I don't want to be and am not grateful for the necessity of the process. I'm only grateful for the result of accepting the Cross; but I can gain the result only if I stop running from the Cross.
I don't need an exorcism beyond the daily renewal of my baptismal vows. What I do need is to pray humbly enough not to fall back into the sort of attitude that once made the greatest of angels into the Devil. To that end, all I can sometimes do at Mass is ask for the grace to be grateful.