I know it’s Saturday but…

a very short lane with two names is really silly.OK, the signs are actually one at each end of the lane which is probably about 150 yards long. Contrée Croix Mansell is the correct name while Crabby Lane was an invention of the artists. And there is another pic in extras.
My saying today is ‘getting on a bit’, which I suppose I am;-(

The idiom "knocking on a bit" meaning getting old likely originated from the sense of approaching or nearing a particular age, similar to knocking on a door to announce one's arrival. The phrase became popular around the 1930s, according to the English Language & Usage Stack Exchange. It is used to indicate that someone is getting on in years, often in a slightly informal or colloquial way. 

Here's a more detailed breakdown:
"Knocking on" as a metaphor:
The phrase likens getting older to reaching a certain age, like knocking on the door of a specific age (e.g., "knocking on 60"). It suggests a gradual approach rather than a sudden arrival. 

Early usage:
While "knock-on" as a term in physics or rugby has earlier origins, according to the Oxford English Dictionary, the specific phrase "knocking on a bit" for age appears to have emerged later, around the 1930s. 

Informal and colloquial:
The phrase is not considered formal or standard English; it's a colloquial way to refer to someone's age. 

Common usage:
The phrase is often used to indicate that someone is getting older, or has reached a certain age, but is not necessarily in a critical or advanced stage of aging.