I don't remember when I learned to walk and I don't remember when I began to walk less and less but I did both with not walking as much being a product of necessity. I have to move around for my work and cars is how I do that so I go from car park to car park with the only walking being car to office, my own or someone else's.
I walked on the weekend but not so long ago I decided to start walking more during my work day, at least where practicable.
The easiest way to do that was to make my meetings close by my own office rather than at my client's offices. At first I thought they'd resist preferring to be in their own environment but I soon discovered that many were happy to get out of the office and meet at a cafe or public space instead.
Now, I use several cafe's a 10 to 15 minute walk from my office and make phone calls to and from the locations so I'm not wasting time, and occasionally just walk and enjoy the snippet of exercise. Considering it would often take me longer than a 15 minute drive each way to see a client I'm actually in front from a time perspective and my body and mind are healthier and happier for the exercise.
We tend to live reasonably sedentary lives these days with a lot of sitting down involved; I don't think that's leading towards a very healthy population so I've really been embracing my new walking working and after a month or so of doing it feel much better.