did you get to your 'destination' and were like "ok time to go back"?
that would depend on my agenda for the day. sometimes there would have already been an engagement scheduled at that destination. i think that is the ideal situation for a mega-walk, is when you actually had to be at that destination at that time, and where a normal person would have taken some form of higher speed transportation. just walk there instead. also, when you get there, it's fun to watch people flip the hell out when they find out where you just walked from