"Written for people to read"

In the Preface to the First Edition of the Structure and Interpretation of Computer Programs Abelson, Sussman, and Sussman say:

Our design of this introductory computer-science subject reflects two major concerns. First, we want to establish the idea that a computer language is not just a way of getting a computer to perform operations but rather that it is a novel formal medium for expressing ideas about methodology. Thus, programs must be written for people to read, and only incidentally for machines to execute.

Whenever I program I try to keep the above quote in mind.