It's getting the awareness of the area ahead of time, so that when the weather changes/roads are closed/etc you are comfortable in changing route on the fly without need to resort to a detailed map and try to plan anything. Just being aware of the towns/etc that will appear on the roadsigns is enough to give you the ability to go explore in the rough general direction you need to go.
As an example, locally, we got stuck in a massive queue due to staycationers trying to get home. We were on a time limit to get somewhere which should have been a 20 minute drive. I didn't have to look at the map, nor program the satnav, I just told Mrs Nutty which turning to take and back roads to follow. Very nasty route, and added 10 minutes to the journey (checking online later), but based on the stationary traffic (still there when we went home 4 hours later) was significantly quicker than sitting in the jam.