It’s not too late to start even at 65. That wasn’t the point. The point was just that it’s worth starting as early as possible. If that’s 37, then good. If it’s 48, then good. You can’t turn back the clocks, so the best time to start stock saving is NOW, if you haven’t done it before (and if you’re not in the terminal phase with some serious illness, in which case it might not be worth starting to invest.)