Staying mentally & physically fit as long as you can, from as early as you can, makes all the difference in your "golden years". Not always golden but, sometimes we can make them sweeter. Eating well is a part of it, also.
When I built this house, 20 yrs ago, I had all the interior doors put in wider, the shower very, very large, with open areas at all. Thus, walkers and wheelchairs could maneuver, shower easily used with hand bars and plenty of room to use a seat/chair, or roll in with a lip adaptor on the entrance. It was a blessing when my mom lived here and needed those things. It will be so if I ever need those accessories in my life.
My DS build a lift/elevator that works to raise a wheel chair up & down at the end of my front porch (or a standing person). It is easily motorized and was a huge assist when mom could no longer navigate steps. He's a framer/builder, so easy for him to do. Plus it looks less obvious than those long ramps. My house is 6 block high, needs a long one to go that route.
with all the mechanized chairs out there now, many could navigate pretty well with some planning. Heck, I see some in town rolling to the store with their heavy wheeled units.....little baskets on front.