When my fingers do your shopping, you eat a lot of spuds

Since my parents are essentially disabled—my mother's had a stroke, and my dad has dizzy spells after getting hit by a bus a year ago—I do their grocery shopping online at Safeway.com. I put in an order in the evening in New York, and it gets delivered the next day in San Francisco, and the cost of having someone pull hundreds of dollars' worth of groceries off the shelves by size and brand and deliver them to my parents' door is $6.95, no tipping allowed. I've been feeling pretty smug about my stroke of genius in locating and carrying out this service. But I've noticed my parents don't seem as enthusiastic—or as grateful—as I thought they'd be. Then, when I was last in San Francisco, I noticed that there were 11—11!— tubs of potato salad in the fridge. Seems my finger slipped on the keyboard. I asked how often such odd quantities appeared in their order, and they claimed not to be able to recall its ever happening before. Perhaps they're more gracious than I give them credit for. We ate potato salad for every meal while I was there and sent tubs home with visitors. And my mother and father kept saying how fortunate it was that we'd ended up with so much and that it was just the right amount after all.