"Do you know what you're in for?" friends at the park asked my son and I when we mentioned we'd obtained permits to make the hike and climb up from the valley floor inside Yosemite National Park to the summit of the iconic mountain famously called Half Dome. 'Uhhhh, not really,' we replied, and we weren't set on pushing ourselves further than common sense and our bodies could take us, so we were very much prepared to stop if we found we couldn't go any further for whatever reasons might arise - the weather, wildlife (we did indeed see a mama bear and her cub on the trail ahead of us...), fatique, thirst, hunger, injury. To our dumb good luck, we made it all the way to the top, and all the way back, without any major injuries or incidents and it was an unforgettable journey, all 16 miles and 12 hours of mostly staring at the ground to watch where we were going.