Just thinking back to iron knob, it was one of the places where it was hard to work out what was going on in the sense that the road was straight and flat, (or downhill slightly at uniform gradient). There were no landmarks ahead. So you pedal and your legs tell you that you're moving, but your eyes say, 'no I'm not, it still looks the same as it did half an hour ago.' So your brain tries to settle the argument. But it's not really sure who to believe. Because it's 45 minutes now and everything still looks exactly the same...
Just thinking back to iron knob, it was one of the places where it was hard to work out what was going on in the sense that the road was straight and flat, (or downhill slightly at uniform gradient). There were no landmarks ahead. So you pedal and your legs tell you that you're moving, but your eyes say, 'no I'm not, it still looks the same as it did half an hour ago.' So your brain tries to settle the argument. But it's not really sure who to believe. Because it's 45 minutes now and everything still looks exactly the same...