Honestly never. The problem is that if you have other stuff in your life that takes priority, like a family, you might not pull your weight OR you might not understand how to manage time. This can happen to people of any ages; kids with family issues or disruption in their home life see a dip in school performance, for instance.

If your talking full degrees im not sure I would have gotten one if I had been ten years younger even after high school. The cost/return is iffy. Certs and associates still seem like they can be worth it and if you can get a free ride well then yeah. I don’t think general age matters as much as financial situation.

There’s a story about Isaac Asimov’s mother Anna Asimov. It’s in one of Isaac’s many autobiographies. Anna and her husband Judah Asimov immigrated to the US from Russia around 1920 and worked very hard operating a candy store in New York while raising Isaac and his siblings. Isaac eventually became a famous author. After Isaac’s parents were finally able to retire, Anna (still with her Russian accent and not-so-great English after all those years) decided to take a creative writing class at the local college. The stories she handed in had grammar and spelling errors like you’d expect, but they had inventive plots, interesting characters, and so on.

At the end of the semester, the instructor complimented her on her work, and asked her if she was related to Isaac Asimov, who by then was quite well known. “Yes, he is my dear son”, she replied. “Oh! No wonder you’re such a good writer”, the instructor said. “Ha!”, responded Anna. “You mean, no wonder he is such a good writer.”

Anyway, it’s never too late. I’ll see myself out.

once Alzheimer’s sets in is when it’s too late.

I’m siding with a lot of the other commenters on here, there’s more ways to learn stuff than going back to school; even cheap or in some cases free classes both online and in person are a thing for instance.

The one exception to that claim is anything that’s regulated in some way/needs a license, eg. driving a semi (need a CDL for that), going into the HVAC business (need a license to handle refrigerants), etc, those you need to go to school for, but things which aren’t subject to government regulations on some level can be learned with a free or cheap course.

I’ve noticed that at 50 it’s harder to absorb data heavy stuff. Memorization isn’t what it used to be. Doesn’t make anything impossible, but…

When the pros no longer outweigh the cons.

I work in a field that offers full tuition reimbursement commonly, so money isn’t a barrier. No con there.

I don’t have kids, so that greatly alleviates time capacity. So some con there but not as much as a parent of young kid(s) would face.

I have progressed far enough in my career and am on a path where another degree won’t really help me reach my career goals, so no significant pro there.

Personal curiosity and ego do motivate me slightly. Even if I never use it at work, I would be keen to have work pay for another degree that I have personal interest in. I also like having advanced degrees solely for the accomplishment. So minor pros there.

In summary, not too late for me but easy to see that’s not the case for everyone else.

I’m 39 and feel like it’s definitely too late for me. I’d be 42+ by the time I’m done and with the way the economy is and the job market in general I don’t think there would be any positive for me to go through that expense.

I basically just missed the boat, all my friends went to school for computer science when they were ~20 so they’re safe now and make an absolute killing. If I were to try that now I’d just join the like millions that can’t find work in that field… For the last 5 years every single day the news has been “omg a recession is coming, it’s coming, it’s definitely coming like tomorrow! Be afraid, it’s coming!” So I never left my shitty factory job, but now I just feel stuck…

Schooling isn’t that important anymore. But you should never stop learning. When you stop you die - or slowly rot away.
You do not need fancy schools to learn new things. They only give you some random piece of paper.
There are countless ways to learn new things on the internet. Free udemy courses, youtube tutorials or even paid tutoring lessons and apps to learn new languages.
You could even buy paid college courses online and fo it at your leisure.
Or just visit couple courses for some small $.

I went back at 30 to become an attorney. I’m now 46 - I wouldn’t do that now, but it turned out I also hated it. Talk to folks around your age in your presumptive industry and ask what they’d say to someone your age looking to get in. Then, BELIEVE THEM.

One of my coeds is in his late 60s. Go to school for the love of learning, and treat the piece of paper as a bonus

I get your point about full time school which may require 2-3 years without income (even though in some countries you may keep your unemployment rights). But often, especially for shorter degrees, there is options in evening classes, whith less hours (sometimes at the price of a longer time) some would even give you real degree. Moreover, if unemployed, sometimes a 6 month training can give you the basis to be hired, either in a manual job, or to fix a missing skill on your CV

Deathbed, you could probably get a certificate or two in hospice

It depends.

If you’re old and wealthy, doing it for the education, not for the income, then it’s never too late. If you’re not, then spreadsheet it. Calculate expected working life and expected income for current career trajectory, and compare with expected working life after education and expected income for new career minus full cost of further education including lost income while studying.

Or if your current works options suck, pursue further education so you can do something that doesn’t suck as long as it won’t leave you much worse off by retirement.

The calculations will be different for every person.

Remember any calculations and expectations will change over time, especially with the advent of AI. So do the calculations, then follow your heart. There’s no guarantees.

I just got my first post secondary at mid-40’s, and lucked into a very sweet job… Hell of a gamble but it did pay off for me. Still, I’m now the junior employee in a tight field and back to the bottom of the pay scale. I might be regretting it in a few years. Flip side, I ran in to some of my old co-workers recently… They are universally eyeing the exit.