I have had to throw away my beloved old Keen mules. The heels wore down to tatters, after ten years, as you would expect, and I found myself slanting backward when I wore them.
These were the only shoes I could walk in for an entire day free of all foot pain. The expensive REI tennis-shoes hurt my feet more than the beloved Keens.
These are the leather shoes Gary called my "rubber shoes" so often that after five years I became convinced they were rubber and I wore them into the Atlantic ocean and the dye turned my feet black.
I ordered a new pair of Keens from Zappos, as close to the originals as I could find, and discovered that a) they were not actually mules, they were those annoying constrictive semi-mules, and that b) I ordered the wrong size.
But that was a blessing, because I found a gray pair on Amazon that was the only one left in my size...
and then a similar used pair on eBay that didn't show much wear on the heels.
The Keen people better not have changed their formula, let me tell you. I don't know what I will do without shoes.