My brother, 56, has been pursuing his Master's Degree at Columbia for over a year now, and he won't complete it until he's sixty (he's going part-time because he has a job), and the take-away is that it's a huge time investment, even as a part-time student. Sure, he cut away YouTube and Facebook, but he also had to cut away the gym. It's a sacrifice.

The other take-away is that if you don't have the math pre-reqs for a course, and you figure that's okay because you've always been pretty good at math & you'll just power through: don't. Take the pre-reqs first, unless you want to needlessly suffer.