I hope to never become this old man that still has to wake up at 6 am to go through the daily grind.
In my profession there are numerous elderly (70+) men still full-throatedly running their practices. They're absolutely my "what not to do" model. I know that some of them have very substantial assets (they chit-chat about their vacation homes) but I assume they either have associated substantial debts, or high spending, or just don't know how to stop.
A fair few are downright incompetent in terms of how the law has changed, which is hard to watch. I'm sure they were top of the game twenty years ago, but that's just not how it works anymore. When I'm getting documents that have been typed on a typewriter, undoubtedly by the elderly gentleman's wife or sister, and they're barely a few lines long--why are you even still practicing? Why do people still hire you?
The worst thing is watching the ones who've kept their competence (and, probably relatedly, their kindness) but are quickly losing their health. I've had multiple trial sittings postponed because ancient counsel are in hospital or physically can't sit through days of court. Worse: every single one of them has come right back to work after (more or less) recovering, sometimes within a day or two of leaving the hospital. I truly like many of these men, and I wish that they would retire and have a restful life at home, with their loved ones--not run themselves into the ground working.
(I've also spoken to women who were back in the office within a week or two of having a baby, which makes me feel physically ill--the overwork instinct of the average lawyer exists in all kinds of troubling forms. And this, by the way, is in Canada, which has extremely good parental leave laws, though admittedly they don't apply to self-employed persons who opt out of paying into Employment Insurance.)
Even if I never pull the ER trigger, I never, ever want to be the person people look at and think, "why haven't you retired?" with either "you deserve the rest" or "you've lost your competence, if you ever had it" tucked onto the end.