remembering a group

Scene: friend asks a simple question, your answer will be a list.

For example: who are the people in your Bible study group?, what are the five one day monument races of road cycling?, what are the four essential elements?

In each case, you know how many items are in the list. We'll call that number n (there's nothing that better shows I am not scared of a number than to label it with a letter).

How many items will you successfully remember? Yes, it's ...

n-1

That's simply the way it has to be.