Jim Quick: What is grit? How do you develop it? And to help you on your Quick Brain success journey, we're bringing back the champion, Dr. Jeff Spencer. We hear about the importance of grit but what does that look like in a person's daily life and how can they use it for their own good? The next episode will be at 8 p.m. ET Sunday night (GMT-8am Monday morning) Follow us on Twitter @CNNQuickBrain and @cnnquickbrains.