What would you do if you were lost in the dark forest at night? The first sensible lesson is that you shouldn't bother trying to find your way in the dark at all, but just stay put until dawn. Because then you won't trip over things? No, mainly because you'll have an idea of direction. The sun rises in the east. But you will be amazed at how many people forget they know that. Apparently, the area underneath a holly bush provides a good makeshift shelter -- they are thick, and evergreen. The next thing to do -- or rather not to do -- is panic, for the obvious reason that unless there is someone there to hear you scream, it will get you nowhere. Just try to think of nice, happy things. There is always a point in films when a person who is lost in the desert or the snow, dehydrated  and exhausted, comes across a set of their own footprints and realizes they have just walked in a huge, round circle. It is wrong to owe it to the unequal strengths or different lengths of your legs. Experiments prove that, without the sun or the moon (or landmarks) as a fixed guide, lots of small errors add up over time so the brain can't correctly identify the "straight ahead" direction. To just get out of somewhere, pick a spot on the horizon and just head for it. There are several ways to find directions in the dark, and by far the best is to establish north using the stars. Most people can identify the Plough, which is part of Ursa Major. It looks a lot like a saucepan. The Plough rotates through the sky, but let's imagine the saucepan lying horizontally  , with its handle on the left. You need to trace a line from the star at the right-hand base of the pan, through the star at the right-hand rim  , and follow it upwards; the north star is roughly five times the distance between those two "pointer" stars. Then drop a vertical line from the North Star to the horizon and that's north. "Tonight is very cloudy and I can't see the Plough." Maybe luckily, it is quite windy. Keep in mind that almost all of our weather comes from a south-westerly direction. (This only works if you are in the British Isles). To find the direction, you can throw light bits of dried-out grass in the air and see which way they blow; or, if there are clouds and patches of clear sky, see which way they blow across the stars. You can also get an idea of direction from leggy plants. If they look as if they have been blown over, they will probably be pointing north-east. If they are simply leaning in one direction as they grow, there's a good chance that is south (they will be reaching towards the sun). The last thing to do is to judge your direction and off you go. Why will people often walk in a circle if they are lost in the desert or the snow?
Because without anything to refer to for directions, the brain will be confused by errors. Because one of the legs is longer and stronger than the other. Because the desert or the snow usually covers a large area for people to get across. Because people usually feel dehydrated and exhausted in the desert or the snow.