I've been meaning to thank you all for the advice - but I've been so busy walking! I got a new pair of Asics Gel Nimbus 17 (my ancient shoes were an old version of this model, and I'd always been happy with the fit). O. M. G. The first few steps I took, I was shocked at how much spring and bounce I felt. I mostly wear flats to work so I'm just used to feeling the hard ground underneath my feet. I just wanted to start skipping!

I've been logging my walks in Strava as "run" so that I can put my shoes in as gear, and keep track of how many miles are on them.