I remember my own father, which is now 91 years old, repeating to me once and again this point from Isadore Rabi’s story about how he became a scientist. He said the most influential moment was that his mother repeatedly when he used to come back from school at a very early age of eight or nine asking him, “Isadore, have you asked kind of a good question today?” Not “What you have learned?” not “What you have observed?” but “Have you raised a good question today?”