DEBUT EPISODE! SOME DAY: Trying to quantify the return on investment in motorcycling is a fool's errand. Even for those who regularly ride vast distances, and therefore enjoy a far lower cost-per-mile, most of the benefits of being a motorcyclist evade any objective accounting. Our Q&A gets into knowing how to recognize mental decline and when to stop riding, either for the day or forever. The Ride Inside with Mark Barnes is on the web at BMWOwnersNews.com.