This question (Calculate true north with a compass and map) got me thinking. I rarely bother adjusting compass bearings for magnetic north. Is this bad? I understand the theory but I just rarely bother. It's never seemed to of caused me any problems.
I mostly navigate in mountainous areas, I wonder if this is more relevant in flat featureless areas? Typically the terrain is just as big a navigational aid as the compass (even in low visibility) and the compass points me at the correct ridge, etc.