(Photo: My Keen Boots after 900 miles on the AT) “I had a nightmare last night,” Red said. “I bought boots instead of hiking shoes and didn't realize until I was on a trail.” I laughed as few people could. “So did you bolt out of sleep screaming while lying on sweat-soaked sheets?” The nightmare was sort of my fault. Earlier, I had been replying to a reader’s question about footwear and I asked for his opinion. “I just woke up confused, thinking, did I actually buy boots?” he said. “Why…