BIG PERKS at work cause me little problems I hadn't foreseen.

For example, at my new job my colleagues give me zero busywork and leave me the freedom to structure my time independently. Therefore, I can't just turn off my brain at work; I have to make decisions large and small all day. I come home tired from both the commute and the effort of learning and thinking all day.

My new company is tiny, with only about eight names to memorize, camaraderie around the lunch table and fast decisions on administrative trivia. But at a big company, if you need to stretch your legs but don't feel like going outside, you can just take a brisk walk in a circle around the office while holding some piece of printed matter in your hands, and everyone will assume that you are being businesslike and productive.

Here that gets me perhaps 20 seconds' worth of exercise, and people are more apt to notice since there's only one corridor.

But a particularly vexing problem is one of self-control. You see, my new workplace provides free snacks to its employees. These snacks include nuts, fruit, jellybeans and Oreos. Oreos! I can convince myself that Fruit Roll-Ups, my other childhood addiction, provide valuable vitamin C and make a healthier alternative to red licorice. But Oreos are just tasty empty calories, at best possibly inducing the consumer to also drink a glass of calcium- and potassium-rich milk.

My boyfriend, who moved to New York from the Bay Area with me, does all of our grocery shopping, and he bakes cookies and other sweets on the weekends, so he wouldn't even think to buy mass-manufactured, trans-fatty gut ballast. The very absence of this temptation at home left me unprepared for the situation at work. The first day I saw the Oreos, I ate about 10 of them in an hour.

Over the past few days, I've cut down my consumption to one Oreo daily, post-lunch. I expect that soon even that will wane. I'll learn to bypass Oreos as I bypass McDonald's french fries, Taco Bell burritos and other corporate food that I used to find irresistible. A big nutrition goal becomes easier to implement with every small decision, and every small bit of behavior I perform that conforms to that goal.

Now, I said that I ate "about 10" Oreos on that first day. I can only approximate; I have terrible trouble measuring unfamiliar things or emotion-fraught items that loom large in my consciousness. As a short person, I'm used to seeing anyone or anything over 5 feet 5 inches as "tall," just as a child thinks anyone post-puberty is old.

My first day in New York, I walked to a meeting point two subway stops away from my origin, since it didn't look so far away on the map. Thirty bone-chilled minutes later, I arrived with a much clearer grasp of the size of this metropolis.

People routinely overestimate the height of impressive professors or celebrities or underestimate the capacity of a car's trunk. But Oreos are uniform in size, in fact so much so that Ben Cohen, co-founder of Ben & Jerry's, uses stacks of Oreos to represent the federal budget in a rehearsed talk he gives to advocate changes in spending. (Each Oreo represents $10 billion.)

So, although I can be sure about the exact size of the temptation I resist, I can't accurately remember how many Oreos I ate when I gave in that once. These small, discrete units add up to something amorphous when I remember them, like subway stations blurring past as I ride home.

It's a short commute by New York standards, but it's still unfamiliar and therefore long to me, and I haven't settled into an unthinking routine yet. Hence the exhaustion.

New York is the largest place I've ever had to learn my way around. But the scale of the place will shrink from my fevered imagining to its actual size, bit by bit, as I visit the big landmarks and make little mental maps. And then, as with all familiar things, I will take it for granted, just as I took the Bay Area for granted.

I'll forget how extraordinary my company's perks are, just as I've gotten used to my boyfriend's cooking and my friends' great conversation, and I'll overlook the grandeur of New York City more and more, until it appears in my rear-view mirror, and I look back with longing and regret.

But that's tomorrow's problem. Today's is Oreos.