Perfect description of a situation where a good compass will prove its value. Not really so necessary in sunny Arizona with its mountainous terrain. Like anything else, the need for a compass, and either other item, depends upon the environment, circumstances, and objective.

I think it is important for all compass users to clearly understand alternatives to compass use - navigating by sun and stars, for example. Be aware of local magnetic variation, which can range from the screwdriver in your shirt pocket to the iron content of the rocks surrounding your location. For that matter, be aware of the limitations of whatever map you may be using (out of date? wrong scale? no topo?)

While I often go months without referring to my compass, it is always in my pack, if not in my pocket. Any decent compass is light, quite reliable, and incredibly useful when you need it - a bit like a FAK (or a knife, matches, or signal mirror) when you think about it......