The idea was so simple: turkey and pastrami on rye with avocado. But today, for the first time I can remember, Lenny's screwed up.

Lenny's is an unbelievably professional and efficient deli and cafe; the one I frequent is on Columbus and 74th Street. Order anything in any permutation, and the speedster talker quickly relays the instructions to an army of food preparers behind the counter. Today, the speedster wasn't in, and this may have been the problem.

First, they produced turkey, pastrami and avocado on a roll. I showed them the order slip, which clearly said "rye." They said okay.

The second production consisted of turkey and avocado on rye. Wrong again.

By this point I was ready to leave and not in the mood to wait for a third attempt. I explained the situation to the cashier. Without one second of hesitation, she said I was absolutely right and promptly refunded me the cost of the sandwich.

Lenny's still makes the best sandwich on the Upper West Side and this is an admirable customer service approach. But we have to be careful not to be too pleased when mistakes are corrected; sometimes people are so excited to see the mistake corrected that they reward the service provider even more afterwards, increasing the incentive to get things wrong.