Just curious, what do you do when you get ill, when your car gets broken, when your fridge stops? Do you study their inner-workings from the ground up? 

Where exactly do you start: protons, atoms, molecules, chemistry, physics, school or university programs?

Or do you go find a person who knows what to do and by some reason believe they will not fool you? And even if they do, you are confident your government would protect you if its something serious?