What was it about Liverpool? What was it about the cultural background of that Northern England city that made possible the birth and growth of the talents that became the Beatles.
But the people of Liverpool always had a way of shining through. In England, as in the United States, there was a great cultural division between north and south, but whereas in the US the people of the south were said to have a more friendly down-home attitude, in England it was the people of the north who lived a less regimented life. (You get an echo of that in A Hard Day's Night when the London policeman had a few words with Ringo about "chucking stones about" and Ringo mutters "Southerner", kind of the English equivalent of "Damn Yankees".)
Especially up north in pubs and homes, the people made their own entertainment. It was their way of hanging together and muddling through. Many of the best English comedians came from the north and Liverpool was a major source. Everyone from childhood on would be expected to tell a joke, play and instrument or sing a song whenever people gathered.
John Lennon's mother Julia was a bit of a life-of-the-party girl and did her share of making people smile. To help out, she learned a few chords on a popular hybrid instrument called a banjolele, constructed like a banjo and strung and tuned like a ukelele. Little did she suspect, I'm sure, where those few chords would lead!