There was one Dear Abby column that has stuck with me decades later. An older person was debating going back to college, and the letter was something like "If I go back to school for four years, I'll be 60 when I'm done. Is that even worth it?" and the response was "How old will you be in four years if you don't go back to college?"
While that's a nice pithy response, it's not answering the question that the letter writer was likely asking: "Is going to college for 4 years in the later years of my life worth it compared to the opportunity cost?".
I guess I remember interpreting it more as a way of looking at the opportunity cost instead of ignoring it, kind of like "If you don't go to college for the next 4 years, what would you be doing instead?"
Although at that age it probably isn't really an economic decision for a better career but rather one of personal achievement if they had always wanted go to college but couldn't when younger.
opportunity cost entails another opportunity, and there is not other opportunity mentioned.
Along these lines, it could be "it's going to cost me money to do this, can I earn it back?" although I don't think that's a typical calculation for a 56 yo considering college.
