I recently reread ”On the Road” and ”The Dharma Bums” to see what was there for me in my 40s, partly inspired by a comment my friend Marcus made last summer: how Kerouac’s writing, as a guidebook for life, is great when you’re between the ages of 18 and 22, but not so much after that. I didn’t dust off my Kerouac to counter Marcus and prove him wrong, but I didn’t want him to be right either.