Part of our tax confusion (U.S.) is that it's very doubtful that any single person does "know the infinite details".
I can certainly verify your earlier statement about benefits in lieu of payment being taxable. In college, during the late 1960's, I worked in the Women's Dining Hall for my meals. No cash changed hands, but that's where I met my wife. Every January, I'd receive a W-2 form from the university showing that the value of my meals had been reported to the IRS as taxable income. Of course, no withholdings had been made since there was no money involved. Cash from other sources had to be diverted to pay the taxes due.
I doubt the guy living at home would be subject to that particular little quirk unless he was somehow employed by his parents and receiving free lodging as payment for that employment. But, who knows, some of those infinite details might be applicable.
Tom Veatch Wichita, KS USA
An armed society is a polite society. Manners are good when one may have to back up his acts with his life. Robert A. Heinlein