I don't bother to take a map when hiking the Multnomah-Wahkeena Loop in the Columbia River Gorge for at least the 50th time!

I do take topo maps for less familiar trails, though. I will check it during rest stops to locate where I am, get an idea of where the trail will go during the next hour or see how close I am to the next stream, camping place, etc. Even when I don't really need the map for navigation, if I come to a viewpoint, I will sit with map and compass identifying nearby mountain peaks and other landmarks. This is not only fun but good practice for actual navigation.

I'd say that the main problem with never looking at your map is that you won't know what to do with it when you really need it!