So many aspects of the human experience we take for granted today were once very different.
Ambrose, Bishop of Milan was remarked upon in his time (4th century CE) for being able to read without moving his lips – something almost all of us do today without thinking. This was considered a 'parlour trick' that only the greatest of minds could master.
Today it's strange to imagine that human ambulation has changed massively in just a few hundred years, thanks to the invention of hard-soled shoes. Whereas once we walked with the ball of the foot first, to cautiously feel for debris or critters underfoot, today we stamp about on our heels (putting our calcaneus bones through stresses they were never 'designed' for).
I've invested in a pair of 'steel socks' made by the Swiss Barefoot Company, constructed out of Dyneema, a wonder material harder than Kevlar. Perhaps by learning how to walk effortlessly in this strange, once-common fashion, I can improve my somewhat slouchy posture.