"If it doesn't grow corn..." is an evaluation technique I use to employ when faced with difficult decisions.
Simply put: "If what you are doing, learning, feeling, saying or thinking isn't making your life and the lives of others around you any better, then why do it?"
It asks us to question, simplify and focus our energy in ways that will improve all life.
"Is it growing Corn?" is a question you can ask yourself about any choice in your life.
If the answer is YES, continue. If it doesn't grow Corn, find another way.