Clapton's guitar solo in "While My Guitar Gently Weeps"

Wow - thanks! That’s a helluva breakdown of the story. When people get their Beatles facts down, they don’t mess around.

The White Album has Glass Onion which has the lines

Here’s another clue for you all.
The walrus was Paul.

So not only was the rumour current but the Beatles were already mocking it.

I don’t see any mention in there, though, of the fact that at least some of those clues were deliberately planted. I won’t argue that some interpretations of album jacket photos were probably people seeing clues where none were intended. But to give one for-instance of a deliberately planted clue: if you’ve got a phonograph, and an old LP of the White Album, you can still spin it backwards and hear it clearly say, “Paul is dead.” There were a few others like it, though.

I’ve only seen one explanation of those clues, but it was published on April Fool’s Day, 2004, so who knows?

I think that was a reference to all the people trying to find hidden meanings in John’s songs. The link says that the rumors started in late 1969, which is when I first heard them. I had just started college and it was a big thing with some very smart people in my dorm. I think the Abbey Road cover really started it off, along with what could be interpreted as grave digging in Come Together. If you want to find evidence of something, it isn’t hard.

That’s my understanding too. FWIW, here’s what Lennon said about it years later (source):