In reality you would need to fill your regulation size hand luggage with extremely heavy items - to reach 23KGs - Gold Bars perhaps
Try car parts for a 1957 Cadillac!
I was called to the Flight Connections security scanners and asked by the security man about our maximum allowance about two years ago (before the 23kg limit was actually published.) I said "as long as the customer can lift it over his head!"
"Not a problem for this guy!" he said "......but I think you should know he's a US Marine and his bag is 47kg and he's trying to take it as hand baggage to Dusseldorf!"
Needless to say, we checked it in but it was a little disconcerting to think it had come all the way from Dallas riding above someone's head!