I happened to run out of cream cheese for by bagel, and I absolutely had to have cream cheese on my bagel," explained Troy Davis as he stood in a Giant grocery store checkout line in the middle of the night. "So I cut it, put it in the toaster to await my return, and ran out to get the cream cheese. However, I am now back here on my second trip, because I forgot the milk to go with the apple pie that followed the bagel." Luckily for Davis, he lives three blocks away.

"Do you think this is enough cheese?" asked an anxious Joel Cohn just before midnight. "Six of us are going to a cabin in West Virginia early in the morning, and I've been put in charge of both cheese and cheese slices . . . Do you think the bag of ice will melt before I get home?" c

In the line next to Cohn were Kathy Waracks and Fred Clarkson, who had been driven to Giant by an uncontrollable desire to bake pie for dessert. But ambition had faltered, and their shopping basket held a boxed pecan pie, as well as grapefruit and avocados. "We decided we were too tired to bake one," admitted Waracks. "But we did buy some whipping cream to put on top of it. No, we didn't settle for Reddi-Whip."

Around midnight, the Giant at Wisconsin and Newark Streets NW, is a bustling place, with several lines open for business. Shoppers leave with three or four bags of serious daytime things like chicken parts, paper towels, birdseed, eggs. Many of them would like to leave even faster than they do. "Someone will say, 'My bus is on the pad! Hurry up!' and you fly," reports night cashier Richard Gidley. "Then, three people back, somebody else yells, 'That's my bus, too! and you fly some more."

On the other hand, there are those with ample time to wander as the night stretches ahead. "My people are at the Swedish Embassy, and I have to pick them up at 12, so I'm just wasting time," reported chauffeur George Scarborough. But it turned out not to be wasted. Although Scarborough had planned to leave empty-handed, he ended up with tommorrow's breakfast. The Heidi bakery proved irresistible to him.

Night grocery trips can result from emergencies; Guy Brandenburg and Gail Murdock's child had just run out of Pampers, for example. A trip may come after an evening class, as it did for Jan Wamsted, or a movie. Kennedy Center-goers occasionally arrive in dinner jackets and evening gowns, says Gidley, who enjoys the note of class this lends the store.

"We get a wide variety of people," says Warren Lewis, the night captian, "They come from the universities, the police station right behind us, the embassies, the zoo. People from just about everywhere bounce in here. There are taxi drivers, bus drivers, doctors and nurses. You get the same crowd over and over again."

If they come in before midnight, the crowd may find the aisles cluttered with groceries being restocked. They may have to settle for pastel yellow Scotties instead of white Scotties, which are hidden behind a stack of cartons. But despite these cartons, night shopping can be a pleasure. It's faster and more streamlined than during the day. There's scarcely time to polish off a couple of National Enquirer or People pages while standing in line. No toddlers crash into you, either.

A couple of hours later, when the real night people appear, both store and customers have changed demeanor. The Giant is nearly empty, the aisles are clear, the lone checker is free to chat. Lights seem three times as bright as usual to an observer who is fighting sleep. Of the trickle of shoppers -- maybe a total of 20 between 2 an 4 a.m. -- several seem dazed. They buy potato chips and Entenmann's chocolate chip cookies, rather than fruit juice and Pampers, often muttering something about "having the munchies."

A few are cheerful and pleased to be there. "It's much easier for me to do my shopping now," pointed out Deborah Crable, whose shift was WRC's news announcer ends at 2 a.m. "I avoid all the mad rush, there's plenty of parking and no hassles. This is just like six in the evening for me." Len Kanthal, who owns "a risque establishment" downtown, glories in the quiet. "Nobody's shaking or twirling anything here," Kanthal observed.

At 2:05, Jerry Scheinman arrived to buy A&w Sugar Free Root Beer for his cohorts who are moving into a new house. "God knows when it will all end -- we seem to have a lot of things," he lamented. At 2:20, a confused young man announced that tonight he had no last name. At 3:10, nightclub manager Jim McDonald reported that he saves his big shopping for Saturday (current purchase: Nabisco Marshmallow Twirls) so that he will not infuriate the tenants in his building by lugging in bags at such a late hour. The guard looked benevolent. The night dragged on.

At 3:45, Marianne Haney came in on a mercy mission. "I'm taking groceries up to WMAL for all those poor people on the midnight shift who are starving," said Haney, who had just finished a substitute waitressing stint. "I bring them healthful goodies plus one sinful thing. Tonight I've got cucumbers, broccoli, orange juice, carrots and apples, but also coconut glazed cake doughnuts. You have to bend a little bit, after all." At 3:50, insomniac Mary Hekman confessed that despite the speed and convenience of night shopping, she'd rather be asleep.

This Giant, like many other Giants, Safeways, Grand Unions, A&Ps and Pantry Prides, stays open 24 hours a day most days; it closes on Saturday and Sunday nights. "They could probably leave the store open seven days a week," Warren Lewis figures. "When we're closed, people try to bribe us into opening up. They bang on the doors and yell. One guy got so mad at not being let in that he turned over a motorcycle and a row of shopping baskets."

One myth must be laid to rest. Throughout the night, many shoppers satisfied many cravings, each in his own fashion. But although this Giant is in a family neighborhood, no doubt well populated with pregnant women, not a single shopping cart of all those surveyed contained pickles and ice cream.