You read the instruction book for cars before you drive them? Really?Usually no, because I would have acquired the knowledge beforehand. For something new and dangerous, I most likely read the manual.
"Low tech" stuff (No read) - Digital camera, phone, razor, meat slicer, computer, paper slicer, paper copier.
"High Tech" stuff (Still no read) - Oscilloscope, Weight Balance, Voltage Regulator, Electronic Circuits, Multimeters.
"Higher Tech" stuff (must read) - Car, Large Machinery, Programmable Machinery, expensive stuff.