That map and compass approach from your grandpa. My uncle taught me the same. Used it all the time in the scouts. Never got lost. Skills like that are still crucial. Batteries die, but a good compass doesn't.
You said you never got lost with a map and compass? That's hard to believe. I've had times where even with a compass, I took a wrong turn because I misread the map. But you're right, these skills are key when technology fails. It's just that claiming to never get lost seems a bit too perfect. We all make mistakes, even with the best tools.
Used to think GPS was foolproof until it failed me deep in the woods. Got completely turned around without a backup plan. Now I always pack a compass too.
Last fall in the Pine Barrens, my compass and topo map had me convinced a trail was on my left. It was actually a dry creek bed. Those tools are only as good as the person using them. I've watched experienced hikers argue over a map for an hour because none of them could match the ridges on the paper to the hills in front of them. Claiming to never get lost with them is like saying you never miss a measurement cutting floorboards. It sounds good until you actually have to do it under pressure. Everyone misreads things sometimes.