Wiley Horne--So. Calif.
No matter the job. It could be electrical, or plumbing, or sawing something, or drill/driving some screws. Doesn't matter. You will eventually get yourself--I should clarify 'myself'--wedged into some corner, or situation not easy to back out of. Or up on a roof. Or down under the floor joists, or up under the roof trusses and it's a 120F, and not easy to get to your shop. With a mouthful of screws or nails.
And you don't have a hammer. No freaking hammer. It's back yonder where you left it.
Hammer in every toolbox.
Over and out.