I am 45, and I want to apply for a PhD degree.

 I am 45, and I want to apply for a PhD degree. Is it okay and possible to do it? Am I too old for this?

(a) Yes, it’s too late.

(b) No, it’s never too late.

Regarding (a) “the system” of grad school is designed to import 22 year olds and spit them out 6–7 years later with PhDs. “the system” is built around a model that you can work 14 hour days, 7 days a week, for months at a time, with either meagre salary (or no salary at all). If you’re also starting a family at the same time, there had better be a *lot* of parental and inlaw support — or there is going to be a train wreck. For my *entire* academic career I was always surprised to encounter PhD students who were married.

Regarding (b) well, given an enlightened and compatible advisor (as well as independent wealth to pay tuition), you never know. There was a grad student in my Department who was a decade older when he *started* his PhD program than I was when I *retired* from the faculty. He’d had a long, successful engineering career, and had the money to pay his own way, and he found the perfect advisor for his work … every time I saw him he looked positively joyful, as if he couldn’t imagine having more fun than working on his PhD.

Frankly, I found him to be rather inspirational.