On the Wagon:
“Only one more for me. I’m supposed to back on the wagon!”
Some people think that this phrase came from when prisoners were allowed one last drink before being carted off (on a wagon). These people are wrong…
The truth is a little more boring than that: it comes from when a ‘water cart’ was used to clean the streets. People who had given up alcohol would apparently say that they’d sooner drink the ‘water on the wagon than take a stronger drink’.
By Hook, or By Crook
There is said to have been a medieval custom in England for the wealthy landowners to allow the workers and peasants to gather firewood from their forests. However, they were only allowed to take wood that they could reach with a hook ( reaper’s bill hook ) or with a shepherd’s crook .
You guys won’t have heard of this one
Telling a Furphy
Pretty much telling a lie or a rumour it originates from WW1 when the carts they brought water up to the lines were made by a company called Furphy as the troops collected water they would use the time to tell stories/rumours etc (i guess it is similar to water cooler talk).
Bush Telegraph is another Aussie specific one pretty much the same but it is basically a network of people in a small town that spread gossip. Aussie version of a rumour mill.
Nope, Never heard of a Furphy, until now 
But have heard of “ Pulling a Murphy”
dumping a boy/girlfriend for his/her best friend…
(I dumped my Ex for her best friend)
“The Duke” John Wayne also used the line “They pulled a Murphy” in in the film Brannigan. think it may be an Irish saying 
Well I’ll be …
I had no idea …
https://fanart.tv/fanart/tv/79172/hdclearart/saved-by-the-bell-5630bd522b299.png
The Red Hand has long been a heraldic and cultural symbol of the northern Irish province of Ulster. One of the many myths as to its origin is the tale of how, in a boat race in which the first to touch the shore of Ulster was to become the province’s ruler, one contestant guaranteed his win by cutting off his hand and throwing it to the shore ahead of his rivals. The potency of the symbol remains and is used in the Ulster flag, and as recently as the 1970s a group of Ulster loyalist paramilitaries named themselves the Red Hand Commandos.
Red-handed doesn’t have a mythical origin however - it is a straightforward allusion to having blood on one’s hands after the execution of a murder or a poaching session. The term originates, not from Northern Ireland, but from a country not so far from there, socially and geographically, that is, Scotland.
"Mad as a hatter " is a colloquial English phrase used in conversation to suggest (lightheartedly) that a person is suffering from insanity.
It comes from the exposure to Mercury in the hat making industry!
Side note: Luton had a large hat making industry and the local football team are nicknamed “The Hatters”
