I'm with Cummins on checking a cold engine. About the only time it gets checked is before I leave on a trip, maybe even a few days before leaving, while I'm doing all the other checks and preps. I know the engine well enough to not be concerned during the rest of the journey.
Might just be the type of dip stick, although his is completely different than mine, but checking at a gas station during a fill-up is a waste of time. There is so much oil in the tube that you can't tell anything about the level, other than that there is definitely oil present. About an hour after shutdown it will be ready to check.