These days, "operator skill" involves a steady amount of thumb pressure on a smart phone keypad. There's no app for acquiring the kind of skills the oldtimers who mentored me back in the 1950's had, so anything beyond swapping parts is "impossible"!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!