Yep, a tank for a grill will be the most common I’d think, but lots of those are going natural gas and hooked up to the house’s supply so the owner never has to replace it.
I don’t even remember learning how to change a drill bit. I was probably 5 or so, and I probably pointed the chuck at my face making clockwise tighten. The same vantage is true for a drill press. I don’t jump up on my workbench to change a bit looking at the chuck from above. I agree with you on CW vs CCW and was just adding more examples of LH threads.

Thanks for the input, I really do appreciate it.
Since I figured that this article is for newbies, (who else would need to be taught how to tighten and loosen the chuck?), how many of those who have never used a drill are going to come across one of those fittings or shut-off valves?
I no longer have either of the following so I don’t remember, but I do believe that propane tanks used on gas grills as well as on campers and RVs also have left hand threads for the connection. I guess then it IS possible for someone who has a gas grill or a camper/RV to have never used a drill before.

Flammable fluids connections and valves often use left-handed threads. Propane and acetylene pressure regulators, hoses, etc. I have a gasoline transfer tank that uses an odd left-handed valve to close the pipe coming off the tank. That one always throws me off because I haven’t owned it long enough to use more than a dozen times yet.