When you play by the rules, defy mental demons, overcome every challenge, and enjoy a walk in the country at the same time - that's being alive.
Golf never ceases to be a challenge, even when it really is just you and the ball out there and nobody else.
Golf challenges you mentally at any age, and when you become my age, it's a challenge physically to try to make your game work as well as it ever did. That's close to impossible, but that doesn't keep you from trying to hit the ball where you used to hit it and make the putts you used to make all the time.