I was never too much of a Beatles fan. They wore suits voluntarily. But I am a history fan. Here's a good coincidence and a guess at its meaning.
I first read about the Beatles in September, 1963, in the New York Times. They'd had releases in America but no hits. They were big in England already.
December 28, 1963 is the release date for "I Want to Hold Your Hand." By January, 1964 America was Beatles crazy and we were listening to multiple releases on "W-A-Beatles-C" radio.
Two plus two equals four. What had happened between September and December, 1963? Something that had made Americans desperate for cheerful relief?
JFK got shot, that's what. In retrospect, the two phenomena seem clearly related.
I have a longer essay-like piece expanding this theory, maybe I'll find it someday.
* Mick Jagger's pet name for the Beatles.