Before committing to becoming a post-grad researcher in my old age, I tried a Stanford University MOOC course in Special Relativity just to see what I was letting myself in for. MOOCs (massive open on-line courses) from some of the world’s top universities are freely available, but they’re not the only internet resources for lifelong learning and re-skilling. Link
From my company’s Health Assured newsletter this month: “With one third of our lives being spent at work, there is little wonder why many look forward to the golden days of retirement.”
To me, the moral of this is: make sure you enjoy your work. If you don’t, and you are fortunate enough to have a choice, then do something else.