I've found courses that aren't directly related to my profession (or making money) to be the most rewarding. For example: https://www.coursera.org/learn/age-of-

I've found courses that aren't directly related to my profession (or making money) to be the most rewarding. For example: https://www.coursera.org/learn/age-of-cathedrals https://www.coursera.org/learn/age-of-cathedrals