It is like all the other buttons, switches and levers that you use. After a while you will learn where they are and using them becomes automatic. I did once pop the bonnet after stopping at a petrol pump, now I know it is the top one for fuel I don't need to see the bonnet and fuel flap levers.
I consider a torch vital. No point in having a spare wheel on a pitch black night if you can't see what you are doing, or even a pump and bottle of glue. In those circumstances I can think of better uses for a phone battery than lighting up the scene even with a charger in the car.