"The only way to know you won't use quantum mechanics ..."
He was counseling a electrical engineering student on what courses to take, and this student didn't want to take quantum mechanics because "I'll never use quantum mechanics." Dr. Burrus' answer was simple and straightforward: "The only way to know you won't use quantum mechanics is if you don't know quantum mechanics."
Whether it's about managing our educational plans in school, learning what we need to run our businesses or be competent in our professions, or learning how to be a complete individual in life, that still seems like good advice.
PS: Yes, I did take quantum mechanics, and, no, I wasn't that student.