After all this hi-faluting stuff about anti-matter and virtual reality, a more down-to-earth, not to say earthy, nugget of information. A year ago, I was assaulted in a monastery by a synthetic-filled duvet with a sheet tucked in underneath it. The result was a hideously swollen toe and nasty developments in the nail. My immensely sapient GP told me that I'd either been wearing football boots that had been too small for me or sleeping under heavy bedclothes, and reaching a conclusion was less difficult than one might imagine. The nail had been torn off below the waterline, so to speak, and would eventually come off. It would, he informed me, take a year for it to grow back properly.
I can now report that he was absolutely right. It takes a whole year from the time of the trauma for the nail on a great toe to grow back. And I bet you really needed to know that.