[purewater]

That makes no sense. You only have to remember one sandwich at a time to decide on the best sandwich, but you have to remember at least three numbers to recall the mean and standard deviation.

[baddox]

Technically, you would have to remember all sandwiches you've eaten up to the point you decide to start keeping track of your favorite.

[aeykie]

The first sandwich you ever have is the best one you've ever had, too.