Cut & pasted straight from Quora - amusing and informative IMO. How true it is I don’t know, didn’t check, but does that matter…
Why do so many British phrases have seemingly illogical meanings, and what’s the story behind them?
In 1887, a British Prime Minister blatantly gave a top government job to his inexperienced nephew—and accidentally created one of the most famous idioms in the English language.
English is less a meticulously designed language and more a historical scrapbook of political scandals, obsolete technologies, and class divisions. Many British phrases that sound entirely illogical today are perfectly rational once placed back into the exact era that created them. While there are hundreds of these idioms across the dialects of the British Isles, looking at a few famous examples reveals how highly specific historical events permanently warped the language.
That 1887 scandal birthed the famously confusing phrase “Bob’s your uncle,” used to indicate that a task is simple or success is guaranteed. Prime Minister Robert Gascoyne-Cecil, Lord Salisbury, controversially appointed his young nephew, Arthur Balfour, to the highly sought-after government post of Chief Secretary for Ireland. The British public noted the blatant nepotism, reasoning that if Robert—or “Bob”—was your uncle, everything would easily fall into place for you.
Another distinctly British idiom is “taking the mickey,” which means to mock or tease someone. This originates from Cockney rhyming slang, a linguistic code developed in London’s East End to allow locals to speak without the police or outsiders understanding them. The original, cruder phrase for mocking someone was “taking the piss,” which was rhymed with the name “Mickey Bliss.” Over time, locals dropped the rhyming half, leaving only “Mickey.” This linguistic evolution turned a vulgar expression into a seemingly innocent but completely illogical modern phrase.
Similarly literal in its origin is the phrase “stealing someone’s thunder,” meaning to preempt a person or take their credit. In 1704, the English playwright John Dennis invented a highly effective mechanical thunder sound machine for his theatrical production, Appius and Virginia. The play was a financial flop, and the theater quickly canceled it. Shortly after, Dennis attended a production of Shakespeare’s Macbeth at the very same theater and heard his exact sound effect being used. He reportedly stood up in the audience and shouted that the management refused to run his play, but they were perfectly happy to “steal my thunder.”
I didn’t know those but I do know a couple ‘bloody’ evolved from ‘by our lady’ , hardly a swear word these days but highly offensive to religous ears, as is ‘crikey’ - ‘Christ blind me’ , ‘blimey’ similar. etc..
Stupid berk was derived from Berkshire hunt, possibly not a phrase to use in polite company.
I think AI is wrong (hurrah!) here. The phrase was first noted in the 1920s as the title of a play.
I was surprised to find that the surname Bliss was indeed used as described, and I’d heard “Arthur Bluss” in that context. Also “Going to see the vicar” 
Replace "Home " with “Brico”
Two Scotsmen go to Hell. A demon approaches the devil and says “Dark lord! Two men from Glasgow in Scotland have been sent here. What should be done with them?”
The devil says "Glaswegians? Their kind are normally very friendly, helpful and honest, so we do not see many such men in my dark domain… Hang them in a cage over the lake of fire for now and I shall check on them later.
"But when the devil flew up to the cage to check on the Scotsmen, he found them happily lounging around with their shirts off.
“What is the meaning of this?” The devil cried. “You’re supposed to be in torment!”
The Glaswegians looked surprised “Naw” they said "it’s pure quality taps aff weather here man. It’s no drab an’ dreich like Scotland, you know that way?
"Fuming, the devil flew to the great thermostat of Hell and cranked it all the way to the top. And the next day, the temperature was so high that even the demons were sweating, the stones of hell were melting and the flames from the lake of fire were leaping higher than ever before.
So the devil was surprised when he visited the Scotsmen and found that they had somehow procured plastic lawn furniture and Buckfast tonic wine.
Raising a glass to the devil, one of the Scotsmen said “Hey big man! If I’d known it was so lovely an warm doon here, I’d’ve done a whole lot more sinning! Weather’s always s***e in Glesga. Always freezin’ ma nuts off, you know?”
“I see.” The devil replied, smiling though clenched teeth "your dismal country has given you a great love of heat. The hotter it is, the happier you are. Well, we’ll see about that.
"So saying, he flew to the great thermostat of Hell once more, but this time, he turned it all the way down.
The next day, the lake of fire was frozen solid for the first time, sinners were frozen in blocks of ice and demons huddled in corners for warmth, their teeth chattering.
But when the devil visited the Scotsmen, he found them jumping for joy, tearfully cheering “Scotland! SCOTLAND!!!”
The devil’s jaw dropped. "What? Why? How? I burn you and you are happy! I freeze you and you celebrate! What is wrong with you?
"One of the Glaswegians turned back and said “Is it no feckin’ obvious ye daft bastart? Hell’s frozen over! Scotland’s won the world cup!”
