There are a multitude of Paul McCartneys. As the one that exists in our physical world wanders about the place, he’s stalked by the ghosts of earlier incarnations – Moptop Paul, Lord Kitchener Moustache Paul, Let-It-Be-Keeping-It-Real Paul, Abbey-Road-Paul-Is-Dead Paul, Rustic Farmer Paul, Wings Paul, Paul-And-Linda Paul, Frog Chorus Paul, Litigation-And-Heather Paul, Experimental-Dance-Music Paul and Thumbs-Aloft-Sir-Paul-Of-McCarneyshire Paul.

Interesting fact: Paul McCartney visited London hundreds of times from the mid-60s on but he didn’t ride on the Tube until the filming of Give My Regards To Broad Street in 1982. Paul McCartney stopped existing as a ordinary human being when The Beatles were signed by Parlophone in May 1962.

One day Paul McCartney and Ringo Starr will be dead and the living remains of the group known as The Beatles will be gone. But The Beatles as an entity is unkillable. Their music will thread its way as an entity through time. And those ghostly spectres of the individual men will remain, a thousand versions of four mortals made infinite, pinned to the consciousness of humanity.

I would love to spend a day riding in the back of Paul McCartney’s mind. He is at a level of fame that few people will ever achieve again. There is almost no inch of the globe that has not played host to one of his records, not heard his voice coming from a tinny speaker. 

Whenever he meets anyone, Paul McCartney is being overlaid by their expectations, their experience of The Beatles, their love or hate for his musical creations, their opinions on his personal life and his political leanings. His personality is a tiny ball at the centre of a vast globe of preconceptions and ideas.

Does Paul McCartney the man exist anymore? I have my doubts.

I’ve always been interested in the way some famous people must have to deal with their past incarnations. A certain kind of artist slakes off versions of themselves as they move through their career, leaving empty skins behind them to be cannibalised by other less original performers. The desiccated bits of Madonna’s leftover looks are being gobbled up by Lady Gaga as I write. 

Madonna, in her current mummified-English-gentlewoman guise, would be unrecognisable stood next to the lace and bow bedecked girl who sang Borderline. If we could regenerate all her personas and put them together in the same room, it’s hard to imagine how Material Girl’s mock-Marilyn-Monroe and the oiled-up avatar of the Sex book would get along. One thing is certain: the malevolent crow Geisha of Frozen would freak them all out. 

Bowie, who celebrated his 65th birthday in silent retirement this weekend, threw himself through a series of starkly different personas. Pop stars ever since have been pinching from the dress up box he filled for Major Tom, Ziggy Stardust and The Thin White Duke. Sure Bowie borrowed liberally from others, especially in the creation of Ziggy, but it was about the combinations he created. I can’t help but think that the cocaine and milk fed figure in Cracked Actor must feel like a very alien creature to the Bowie of today. 

But while Madonna and Bowie are two obvious pop shapeshifters, it’s the predicament faced by Paul McCartney that fascinates me most. He has been famous for the longest of the three and played numerous roles during that time, all of which remain extant to a greater extend that the past personas of the other two. The Beatles remain so central to popular culture that the Paul frozen barefoot on Abbey Road and Sgt Pepper’s conscript exist alongside today’s Sir Macca ThumbsAloft variant. 

I once sat next to a camera man at a dinner. He’d worked on Give My Regards To Broad Street, McCartney’s 1984 film (filmed in 1982) which features him busking anonymously outside a Tube station. My dining companion told me that before the filming, Paul had never been on a Tube train before. The first time he rode the Underground was 21 years after The Beatles first rocked up in the capital to be roundly rejected by cloth-eared record execs certain that “guitar groups were over” in 1961. 

The time it took for McCartney to venture onto the Tube is one of my favourite pop facts. It’s not important in the story of his career or surprising that Brian Epstein didn’t expect his boys to schlep around on the Circle line. It’s a little detail that hints at how unusual McCartney’s life has been since he was 19 years old. Beneath the layers of popular and critical opinion there’s a kernel that is the “true McCartney”. 

It’s clear that Paul McCartney tries to hang on to that. Two years ago, he told the BBC: “I’m happy to talk to people on a one-to-one human basis but the minute they turn me into this celebrity that I’m pretending not to be for that minute, I sort of say no, I’m not going to do that. I will just go shopping or go to the movies on my own…” But whatever he does, those other incarnations of Paul McCartney conga along behind him. 

McCartney has called fame “a weight I’m happy to carry” and he is alone among The Beatles in still having to truly carry it. He wasn’t gunned down like Lennon, who dissolved into a cloud of myths, legends and laughable licensed products, and inhabits a far more static character in the collective consciousness. He’s the last living Beatle – George Harrison is gone and Ringo Starr might as well be having descended into a kind of semi-living cartoon afterlife. 

Why I am I obsessing over this idea of past iterations of the famous? Because technology is tying us all to previous versions of ourselves now in the way that albums and films preserve versions of celebrities in artistic amber. Searching my Gmail inbox this weekend, a string of unrelated emails surfaced from the gigabytes of forgotten messages and gave me a snapshots of 2006 Me and 2009 Me, of the Pensions World staff writer meeting people who read his fiction online in real life for the first time and the Q section editor struggling to get a grip. 

I haven’t changed myself so drastically that the old me would stare blankly at the new me if we met in some time travelling snafu., I’m not  the San Diemas slacker Bill & Ted coming face-to-face with their society-saving Wyld Stallyns future selves. Instead, I’m more confused than those earlier incarnations were. While they were unsatisfied with their jobs, they had a plan and a direction to head in. 19 days before my 28th birthday, I’m wondering about what iteration comes next. 

Dawn H Foster tweeted this weekend asking whether she was alone in feeling less intelligent now than she did when she was younger. I know exactly what she means. Those earlier versions of me were more certain in their ability because life hadn’t chipped the armour plating of arrogance off them. I’m at a point where I have let that go too far though and wear away at the confidence beneath it. Whether the next incarnation of myself turns out to be paranoid and shaky like the Thin White Duke at his darkest or on the cusp of a new prospects like McCartney circa 1961 is up to me.