You can never get the dozens of stupid little parts to stay in one place while you fit the two halves back together. Then the wiring, why must it ALWAYS get trapped between the 2 shells? And the blasted screws! One of then is certain to drop 3 feet to the floor, with not the slightest provocation and totally vanish. Then, contrary to all the Laws of Motion of the Universe, it transports itself 45 feet to the other end of the shop, behind a cupboard. But somewhere in the world there's a production line where a smiling deft-fingered operative is assembling one of these things every 10 seconds, with her left hand, while holding jolly conversations with her workmates!
Why me, Lord, why ME?
