I would walk five hundred miles

Or so it seemed. "Let's do a couple of caches" we thought "and then do the shopping on the way home." The first one was pretty straightforward; the second was a little trickier; the third claimed to be 'a short walk of less than a mile'. Great - plenty of time. We got the first waypoint easily, though reaching it was weird, going down a sloping tunnel without any light, and set off for the second. We walked, and we walked. And then we walked some more. There aren't many ways to get lost on a towpath, especially when you're going in the required direction. "Less than a mile" we reminded ourselves. When we'd walked 1.2 miles with no sign of the waypoint we decided to call it a day. We'd got back to within about 500 yards of the first waypoint when we spotted the second (missed because we don't have eyes in the backs of our heads and were looking where we were going!), took the figures, ummed and aahed, discovered the cache site was less than 0.2 miles back where we'd been, ummed and aahed a bit more, and went for it. Found it within minutes. Done properly, the walk would have been about half a mile, not just under the three that we did.

The shops were shut by the time we got there.