The getting lost and walking in circles
Ok, this is probably silly, but I'm curious...
As you have seen countless times from real life reports or in fiction, one weird consequence of getting lost in an environment where it is not possible to take reference points is that people tend to go around in circles, eventually even returning to the point where they left.
I have no idea why this happen... or if it actually happens that much. One explanation I heard simply didn't convince me at all; that we have an hard time walking in a straight line, invariably describing a circle. This doesn't explain the same situation happening on rough terrain like jungle, for instance. Also, some people report having walked for hours only to return to the same place. This would mean a big radius and I find it hard to believe we could unknowingly plot such wide and perfect circle while walking.
What do you know about this?