We are in the midst of Lent, of course, and that is traditionally a season of penitent prayer, almsgiving, and fasting. I always find the fasting part of it fascinating, because it's the part I'm completely incompetent at. Penitent prayer really doesn't require any more than being able to say you're sorry and think of how to do better; almsgiving requires little more than just setting some aside and remembering to get it somewhere. Confessedly I've failed at both, but it's not a competence issue. I really and truly do not fast well, though.
I am very much the sort of person who doesn't pay attention to these things. I don't usually have regular meals -- the whole rule of "one full meal and two small meals" for mandatory fast days is completely useless to me since almost all my meals consist of light snacking over the course of a few hours. Sometimes, in any season of the year, I will forget to eat almost entirely. Normally I just eat when I'm hungry; a bite here, a bite there, while doing other things. (I am a consistent multitasker when it comes to eating.) I have never succeeded in giving up anything for the entire period of Lent; I usually only remember that I'm supposed to be giving something up after I've finally failed to do so. The same happens during Fridays of the ordinary year; in principle I don't eat meat on Friday, but I fail at that about every three to four weeks. "Ham is meat," I think, as I finish the last bite of a ham sandwich. "Today is Friday," I think, fifteen minutes after I have finished a pepperoni pizza. You might think I'm exaggerating, but no.
There are lots of reasons for traditional practices of fasting. But one of them is just to remind ourselves that there are many parts of our lives to which we simply don't attend, at least not in any serious way. Maybe things are just fine there, maybe not, but obviously if you never look, you never know. Bad habits build up most easily where you cannot see them, and we are less transparent to ourselves than we usually think. It's not that reason has to pay attention to everything all the time; it's that it has to look around sometimes at things it usually leaves to themselves, tidying them up a bit, making sure the whole thing's working as it should. And sometimes things have become quite bad (or, if not yet bad, absurd in a way that could be bad someday) without one's ever realizing it. It's useful, for instance, to look around and realize that, while I don't really eat too little or too much in quantity, an inordinate proportion of my food pyramid consists of pizza or chips and dip. In those cases something needs to be done, and the first thing that needs to be done is to get reason's foot in the door by actually paying attention for once.
Fasting is a spiritual practice. It is not about the food. It's not even really about how well one succeeds at restricting oneself, although I hope most people's failures in it do not reach the height of ridiculousness mine sometimes do. It's really about avoiding the thoughtlessness that lets anything take root, about looking around at your life occasionally in order to pay attention to the little things. That's the primary discipline. There are other things, of course, since it's a penitential practice as well as a disciplinary one, and also (both very important, but too often forgotten) a way of marking the importance of a new beginning and a way of freeing oneself of unnecessary distraction. But all these presuppose that you've undergone the discipline of having a good, rational look around.