Tom, the real answer is ALL OF THE ABOVE...but people who are normally calm can panic, people with GPS can't get reception, people with maps can't see the landmarks, woodsmen find the moss growing on all sides of the tree, overcast sky obscures the sun....etc. etc. There are tons of technology answers to your question, but as others have mentioned, all powered tech.can fail you in an emergency and should never be relied upon 100%. If you are going remote, go prepared.
I generally like/use gps technology but when I am in a remote area, I am always at least minimally prepared for an unplanned overnight before I ever leave my vehicle/camp, as no one ever plans to get lost and besides being lost, there is injured and unable to move which may be even worse.
I am a firm believer at minimum in always carrying a small compass when in an unfamiliar area as even if you are not sure exactly where you came from(bad planning), you can at minimum pick a direction and keep from walking in circles.
Carrying a small pocket emergency kit with reliable fire making ability when you are in the bush also tops my list as fire makes a great nighttime companion, can signal for help (see lighting up a tree in the post above ) as well keeping hypothermia at bay.
Because its very wet here in Western Oregon, multiple ways to make fire is at the top of my list. I carry a small tin (3x4x1) that has: waterproof matches/striker, small lighter, spark generator, tinder, char cloth, pitch (fatwood), flat emergency whistle, 20' or so of 10# mono fishing line to use for bout anything and my 1/2" dia. button compass.(weighs bout 4oz. total) Toss in a couple bullion cubes and use the tin for a pot...With that I include a $0.99 mylar blanket that can double as shelter if need be and can be cut into strips to mark your trail and/or location to keep SAR personell from walking right by you as you sleep. Drop both in the bottom of the finds pouch before you leave on your hunt, and you won't know its there till u need it.
Once it's overcast, foggy, rainy, snowy, dark etc with limited visibility the wild places all get looking the same real fast.
Doesn't matter where we live/play in the remote areas people get lost, some overnight lost, some never come home lost, and no matter where you are, once you become lost it will trigger events that will be putting lots of lives at risk by all the people who are going to be trying to find you during the SAR mission that follows. With a little planning, the life you save may not be your own......