I made it through my freshman year of college and all of high school without consuming any caffeine.
Over the summer, I consumed my first caffeinated beverage; it was a diet Coke with lime, and I only drank it because someone left it in one of the rental houses (left a whole case of them, actually) I was cleaning. It was a Saturday (for those not in the know, this is changeover day, at least for cleaning companies on the Cape) which meant that we started an hour earlier than usual and worked until late afternoon. A usual day started at 9 and ended at about 2:30; on Saturdays, I got to work at 8 and worked as late as 6. There's also a lot more pressure on Saturdays, mostly because we're doing a different kind of cleaning. On weekdays, the emphasis is often more on doing a thorough job; two people might take an hour and a half or two hours on a two-bedroom house. On Saturdays, you really have to get houses done in under an hour (some people can do a rental house in half an hour), and there are more of them. For the person driving (which was usually me) this puts an additional load on your mind: you have to find your way from house to house without getting lost or putting too many dings in the car.
I felt relatively unconflicted about drinking caffeine in these circumstances. In fact, maybe I should clarify why I would even consider feeling conflicted in the first place. As a person who has never really been able to fall asleep in under an hour, I was extremely worried, as a child and then as a teenager, that caffeine would keep me up all night (my fears were probably justified, if not on chemical grounds then on psychological ones). When I finished working on a Saturday, though, I felt like death. We were working fast, so I never stopped for lunch; I had to get up at 6:30 in order to bike to work. By the end of the day, my symptoms were positively flu-like. Fortunately, I had Sundays off, so I could sleep in. Caffeine took the edge off, allowing me to get through the day and get home before I collapsed. I never had any trouble sleeping after changeover days.
Caffeine use during the school year caused me more trepidation. I'm not taking a particularly heavy course load this semester, and I'm not working very many shifts in CDS. There's no good reason I should need caffeine to get through the day. I should be able to just focus, right? Just get my work done before midnight? It's all stuff I like to do, after all: reading, interpreting, writing about it.
It's just that I'd like to focus more, and better, and get myself to stop watching Netflix1 occasionally in order to get my readings done. It's not that I didn't get the work done, in the first month of school; it's just that it was an effort to sit down and do it. I see that I am being unclear. For illustration, I am going to use gifs from Grey's Anatomy, because I think it's kind of meta.
Here is my brain on six hours of sleep a night2 , without caffeine. There's really not much to say about this gif. It just perfectly represents my thought processes, in the sense that, when at three in the afternoon I sit down to write a paper on a poem by Keats, there is absolutely no rationality, focus, or coherence in my thought processes. Notice that, despite Christina Yang's somewhat spastic and unfocussed movements in this gif, there is no real movement or interaction with anything else (like, say, a poem by Keats). Is she trying to say something? No one will ever know.
This is my brain after consuming 20 ounces of something called "Mtn Dew." In this gif, the blonde-haired woman (Arizona Robbins) should be understood as the text, and the dark-haired woman (Callie Torres) should be understood as me. Notice that the text is standing still (or, in this case, sitting still) and presenting a beatific countenance that nonetheless suggests the presence of a multitude of complicated emotions that are just crying out to be interpreted. Note the grin on the face of the reader. This is how I usually feel about reading.
So what's next? Will I become completely dependent on caffeine to get through my day? I guess we'll find out, because midterms week is coming fast...
On the one hand, I love Netflix; it helps me relax and keeps me from going totally crazy. On the other hand, when I'm too wrapped up in the emotional travails of the denizens of Seattle Grace Hospital to write that final draft of a paper, I curse the fact that I have access to streaming movies and TV at all.  I'd also like to make a disclaimer that for many people--many college students--this is a totally wonderful and adequate amount of sleep. Apparently, my sleep needs are around ten hours a night, which is ridiculous, but I just wanted to establish that fact instead of letting you think that I am ungrateful for the relatively plentiful hours I am able to spend asleep.