How can we learn if we don’t sometimes fail?

I’ve run into a problem. My first handspun socks, the product of the Great Shetland Experiment, are experiencing severe structural failure. Barely past their first birthday, these beloved objects are wearing out, and quickly. I darn, I patch, I try to save, but as soon as I do, new holes appear. The same thing is happening with another, newer pair, too. Since I made these socks from the yarn up, I’ve only myself to blame, so I’d better figure out what went wrong.