I realise that I am getting older. The stairs, the mountains, which were no problem at 30, became a challenge at 40 and made me really proud at 50, are now simply no longer manageable. That's okay. I can no longer manage some things. That's okay. And I don't need to apologise for it. What would be fatal would be to rest on my laurels and not try anything at all. And then it would be misbehaviour.
You, old? That's like oil and water!
Jokes aside, there's no shame in admitting that your body has given you the best years of your life. So what if it starts to slow down a little? What if it needs a bit of rest or wants to adapt to a new lifestyle?
And yes, I agree—keeping that spirit alive is essential. Without it, it would definitely be a disservice, if not outright misconduct and malpractice!