Of course, that was purely the financial return. Since I only ever studied what interested me, enjoyed the college experience, and never worried about grades or anything, the real returns are almost definitely positive.

That's always the bigger problem—the counterfactual of what you could have/would have earned working instead.

Opportunity costs are one hell of a perspective 

denlillaapan

econ

Is Your Master’s Degree Useless? (The Economist)

I only paid for some of my undergrad, but I went to an inexpensive school and had a partial scholarship. After that I took classes that my job paid for and got paid a stipend during my PhD.

Even so, I bet my return is only slightly positive, because that's a lot of foregone wages and work experience.