I have a pair of cycling shoes in my garage. They're made of thin leather attached to a stiff sole. Screwed onto the sole, there's a cleat that makes walking difficult by raising my toe above the level of my heel. But the cleat made it much easier to ride a bicycle. See, there's a slot in cleat that fit perfectly into part of a quill pedal before the whole foot is cinched onto the pedal with a leather strap.
These were my first pair of cycling shoes, which I acquired not too long before clipless pedals became quite so ubiquitous. I remember specifically (though my memory may be faulty) that my parents questioned the wisdom of me buying these shoes. They were kind of expensive for something so specialized, or for something that I'd only be able to use for one very specific activity. They asked whether I intended to continue cycling, or whether it would be something I moved on from before long.
It was a valid question, which I dangerously answered 'yes' ... how could I really know what I'd be doing in the future?
The last time I wore those shoes was for the first triathlon I ever did. It was a winter race, and the stages were started individually, which meant that there was plenty of time to change clothes between swim and bike, and between bike and run. I cinched my shoes onto my pedals at the start of the bike leg while everyone else simply clipped in.
But that day was the renewal of my love of cycling. I'd spent a couple years away from riding much at all, but that day I felt again the thrill of working hard to go fast. That day I also understood the need (need?) to purchase new cycling shoes that fit new clipless pedals.
Were those leather shoes a good purchase? I'm happy to say that my dangerous 'yes' was accurate. I now have others that work much better; but I still keep those original shoes hanging in my garage ... just for me.