Habit, in fact, comes from the Latin word meaning dress and then, in the Middle Ages, came to mean the dress worn by the religious. We still call a nun's outfit a habit. I love this as there are two sides (at least) to habit just as there are two sides (at least) to being religious.
On the one hand, habit lets us focus on what matters. It removes the banality of the everyday, banishing it from the duty of intelligence, reason, decision, contemplation. If we wear the same thing every day, we are free to consider other things such as our relationship to god. This is one aspect of a certain religiosity: a disdain for the things of this world, privileging the spirit over the body. Habit facilitates contemplation of higher matters.
On the other hand, habit blinds us. By removing decisions about the everyday, we begin to ignore the here and now, the flow of the cosmos, the rush of life. Sure, what we wear is not so important in the grand scheme of things. But, then again, nothing is that important in the grand scheme of things and hence everything is important in the grand scheme of things. This is the other side of habit and the religious: habit blinds us to reckoning the eternal now, to the ubiquity of god's presence — for god is in all things, even our black jeans. In this case, habit blinds us to the glory that abounds.
There is another side of habit that at once affirms and denies the habituality of habit. Every morning I wake up and do basically the same things — my neti pot first, then my granola. From afar, this sure looks like both sides of habit: I've eliminated decisions so I can focus on higher matters (such as which coffee to make) and I've blinded myself to the now. But, from within, it doesn't feel like habit. Each morning, I wake and consider what I want and, usually, I come to the same thing: I want to do that neti pot because, man oh man, it feels incredible. And then I consider my breakfast and think: You know what? That plain granola, a little shredded coconut, some nut butter, and rice milk all nuked for 30 seconds sounds perfect!
Deleuze would call this repetition. Repetition is premised on difference: if this weren't different from that it would be the same thing and hence wouldn't be repetition. If this is the same as that then it's a copy, not a repetition. From the outside, repetition may look like copying but from the inside they couldn't be more different. This difference is the movement of affirmation. (I want to say that the addict begins by enjoying the drug, affirming it. And then moves into just needing it. Addiction, I believe, involves the movement from repetition to copying.)
To affirm the same over and over again, to see the new within the old, to take what already exists and discover the teeming life within it is nothing less than miraculous. Think about a blues solo in which BB King plays the same note over and over. The first couple of times he plays it, it doesn't seem like anything. But as he repeats it, as he affirms that note over and over again, a kind of mania kicks in, delirium, the madness of the now. It is the absolute affirmation of the universe: This! This! This! This! To infinity! That is joy unbridled.
In Either/Or, Kierkegaard juxtaposes the seducing aesthete with the married, ethical judge. The seducer sleeps with a different woman every day; the judge sleeps with the same woman every day. Which is repetition? For Kierkegaard, the seducer copies as every woman becomes the same thing, becomes a concept of woman. But the married man must find the new, must find the erotic, in the same woman day after day for his entire life. This demands the relentless internal movement of affirmation, to summon a Yes, Again each day! (For Kierkegaard, repetition is the very (moving) ground of Christianity, what separates Socrates from Jesus: for Socrates, everything is memory, a living backwards; for Jesus, everything is about being reborn, being born anew, memory lived forward: repetition.)
Of course, in our lives things are a whole lot messier. The guy — or gal — who sleeps with a different person every day (more or less) may very well find the spectacular in each encounter, the new, the different: the seducer may very well be reckoning the now. And the married man, more often than not, does not repeat but copies, falls into a blindness, failing to affirm much of anything.
I love walking into a bar and seeing the wall of booze. All these choices! All these different ways of going! All these moods! What is right for me on this night? Shall it be the weight of whiskey, the sun of tequila, the herbs of gin? These days, 99.99% of the time, it's gin on the rocks. But 83.75% of the time, it's not habit that's propels this decision. It's affirmation. Yes, gin. Gin again. Gin anew. This, for me, is the challenge and delight of a bar: the negotiation of habit, a reckoning of how I go in the universe.