Nearly everyone sees themselves as more competent than they actually are as they age. It's hard to give up the [[Previous version of yourself]], even when things are noticeably declining. It's natural to view previously routine tasks as, well, routine.
Few recognize their decline, or admit it to themselves, or make changes based on those declines until *after* they probably should have.
Simply put: it's really hard to get ahead of getting old.
You're almost always dealing with situations that you probably should have acted on before today. As a result, if there isn't a part of you that thinks it's still too early to start planning (or, more to the point, to start implementing the plan), then you're probably already late. That's just how it goes.
An unfortunate outcome is that the longer you wait to prepare for old age, the fewer options you have, and the more decisions get made *for* you, rather than *by* you.