Caleb was 85 and still asking for the hard hill country. Age isn’t the thing that retires you. Attitude is.

At eighty-five he asked for the difficult ground rather than the easy allocation, which is not what anybody expects of that age. What retires people is almost never the number. It is the moment they decide the demanding version is for somebody else now, and that decision is available at twenty-two as readily as at eighty. Plenty of young people have already made it.

Ask for the harder assignment this week. The tougher subject, the longer shift, the position nobody wants. Then notice how much of your reluctance was actually about effort rather than ability.