In a famous 1970 Rolling Stone interview, Jann Wenner asked John Lennon, "Are you the Beatles?" to which he replied:
LENNON: No, I'm not the Beatles. I'm me. Paul isn't the Beatles. Brian Epstein [their first manager] wasn't the Beatles, neither is Dick James [later manager]. The Beatles are the Beatles. Separately, they are separate. George was a separate individual singer, with his own group as well, before he came in with us, the Rebel Rousers. Nobody is the Beatles. How could they be? We all had our roles to play.
WENNER: You say on the record, "I don't believe in the Beatles."
LENNON: Yeah. I don't believe in the Beatles, that's all. I don't believe in the Beatles myth. "I don't believe in the Beatles"—there is no other way of saying it, is there? I don't believe in them whatever they were supposed to be in everybody's head, including our own heads for a period. It was a dream. I don't believe in the dream anymore.
(Source)
This is pretty heavy stuff coming from a guy whose life was shaped by being a Beatle, but it's also indicative of the man behind the tinted glasses: John Lennon always had, even through his years in the band, considered himself more of a solo artist, and finally in 1970, was able to make that dream into a reality.
In the same interview, Wenner—always the straight-shooter—asked Lennon if he considered himself a genius. Lennon replied:
When I was about 12, I used to think I must be a genius, but nobody's noticed. I used to wonder whether I'm a genius or I'm not, which is it? I used to think, well, I can't be mad, because nobody's put me away, therefore, I'm a genius. A genius is a form of madness, and we're all that way, you know, and I used to be a bit coy about it, like my guitar playing. If there is such a thing as genius—which is what...what the f--k is it?—I am one, and if there isn't, I don't care. I used to think it when I was a kid, writing me poetry and doing me paintings. I didn't become something when the Beatles made it, or when you heard about me, I've been like this all me life. Genius is pain too. (Source)
While most people upon hearing this would emphatically jump up and say, "Hey that guy's a raging egomaniac!" they'd be right, and Lennon even said as much. However, there's absolutely no denying the fact that Lennon was, in fact, a genius. He always felt different, and always was punished for it rather than celebrated, until he finally made it big with the Beatles. He was the philosopher, the acid to Paul's honey in their songwriting team, and always the Beatle most lost in his own head.
However, in 1966, after the band had already completed such hit albums as A Hard Day's Night, Help!, and Revolver, Lennon started feeling a tug that he couldn't ignore. He was starting to drift away from his musical fraternity. He was sick of pandering to the public and producing song after song to feed the insatiable appetites of his record label and his fans, but he couldn't see a way out. And then he met Yoko Ono.
Arguably the most misunderstood and hated rock and roll wife of all time, Ono came along one night and stole John's heart, much to the dismay of his adoring fans and the other Beatles, who collectively behaved like a person bitter at their best friend for falling in love. Yet what everyone failed to see is that John's break from the Beatles really wasn't Yoko's idea. All she did was give Lennon the little push he needed to take his life in a new direction, something he'd already been planning to do.
Things really started to change when the band went back into the studio in the summer of 1968 to begin recording what would later be known as the Beatles White Album: Yoko was there, and the boys weren't happy about it. Figuring that she would just be another passing fancy, they tolerated her with a forced pleasantry, but soon began to resent her as John became more detached from the group. In fact, just days after the release of The White Album, John and Yoko released their own first album, Unfinished Music No. 1—Two Virgins. Both albums received immense public attention, albeit in very different ways. Though Lennon's biographer called The White Album "a blueprint for a breakup" (source), it remains to this day one of the best Beatles releases.
It's true, however, that the classic Lennon/McCartney fluidity isn't present on this album. During the recording sessions, both Paul and John wrote many songs completely on their own and didn't look much to each other for feedback. John's main hits from The White Album are "Revolution," "Happiness Is a Warm Gun," and "Yer Blues," whereas Paul shines through in "Blackbird," "Martha, My Dear," and "Ob-La-Di, Ob-La-Da." Still, the album got rave reviews and no one could foresee the imminent demise of the Beatles.
Meanwhile, Two Virgins was getting some very public attention of its own. In arguably one of the most infamous album covers ever, Lennon photographed himself and Yoko standing full-frontal naked with their arms around each other. The back was their naked backs, with the two of them looking over their shoulders. The point, according to Lennon, was to show the public that he and Yoko were just regular people like everyone else; the picture was purposefully unflattering in order to hammer home this idea.
During this period, plenty of other forces were at work which began to dissolve the Beatles infrastructure while the world became an even more fractious place. Their company, Apple, fell apart; Paul married Linda Eastman (later Linda McCartney); John announced that he was quitting the band; Paul and John fought via their respective solo albums' song lyrics; Woodstock happened; Nixon was elected president; the students of Berkeley rioted; and eventually Paul sued the Beatles due to management strife. However, in an unexpected period of solidarity and reinvigorated collaboration in 1969, the Beatles came together for the last time at Abbey Road studios, enlisting the help of their original producer, George Martin while working together wholeheartedly (though everyone could tell this was the end).
The Beatles released Abbey Road in September 1969, on which this iconic cover photograph appears. It's arguably one of their best albums, and also their last time working together in the studio as a cohesive whole. Despite the success of Abbey Road, however, the Beatles were already done before it was released in 1969. John told Paul during a meeting with the record labels that he wanted out and that was that. As he said in later interviews, "I started the band, I disbanded it. It's as simple as that." (Source)
As far as the other Beatles and the fans were concerned, however, it wasn't simple at all. Paul McCartney, especially, took the hit hard and things were never really the same between the two old friends again.
Fast forward to 1971. Yoko and John had just gotten done with several years of peace campaigning, forming the Plastic Ono Band, and undergoing primal scream therapy and John had written one of his most personal and vulnerable albums ever. Now it was time to make Imagine, the album and film which would represent a high point in his solo career. And he was proud of his new life, family (he and Yoko had a son, Sean), and career.
As he later told Playboy magazine, "'Imagine,' 'Love' and those Plastic Ono Band songs stand up to any song that was written when I was a Beatle. Now, it may take you 20 or 30 years to appreciate that, but the fact is, if you check those songs out, you will see that it is as good as any f---ing stuff that was ever done." (Source)