Alan Cooper

to minimize mouse movement

The OXO Good Grips line of products was originally designed to be easy to use for people with arthritis. It turns out that satisfying this user with the most constraints (and a tiny portion of the total market) satisfies the bulk of customers greatly.

If you are involved with a product team, design team, or client who claims to be using personas, ask them how their personas were constructed, what user data was gathered, and how it was analyzed to create them