Yeahhh, I'm turning 70 in a couple of months. I committed to doing a guided climb on Mt Baker with my son a few days after my BD. I'm motivated by not wanting to disappoint him. It's a lot harder ramping up your fitness level and maintaining it after 60, as Bob said. Living at 6500" elevation (now) in the Lake Tahoe basin helps, with all the outdoor activities right outside my front door. As long as I can keep doing it... Bob's my hero, too.