I was trained as a child to locate landmarks wherever I was

This is just a carry over from the last 400 years of Americans going back to the first Pilgrims or going back thousands of years here in the U.S. through native American Tribes. You are always looking for landmarks to geo-locate yourself. You look for mountains, you look for specific trees and rocks that look differently from other trees and rocks. If you are closer into civilization you look for buildings or farms or ranches to geo-locate in relation to them. 

For example, you are driving down a road nearby or in the wilderness. When you get out of your car or truck or before you begin  sizing up what is there whether it be trees or meadows or mountains or whatever. When you park your vehicle you begin geo-locating yourself so you can always find your way back to your vehicle.

For example, I often will not hike into areas where it is all trees for miles and miles unless I'm traveling on foot with others who have traveled this route before. Why?

Because trees and trees and trees and more trees without being able to see out is very potentially dangerous and an easy place to get lost and not know where you are. Then the only way without a phone or GPS device to know where you are you might have to climb the biggest tree around to try to see out to get your bearings. And without someone familiar with this trail you shouldn't go into a place like this alone without maps at the very least or a GPS device or a phone (if there is any signal at all).

For example, most wilderness places in California there might be NO SIGNAL on your cell phones at all.

For me, especially if you travel around Mt. Shasta to the north or the east there are areas where you aren't likely to see anyone at all for up to 50 miles at a time. IN these areas you better have forest service maps and know how to read them or you are going to get lost even in your car or truck or motorcycle or bicycle.

So, it is quite possible to get lost in the wilderness even in your car, truck or on your bicycle or motorcycle as well if you aren't familiar where you are going to.