Dissociative Identity Disorder (Multiple Personality Disorder)
How many alter egos can a person have?
A person living with DID may have as few as two alters or as many as 100. The average number is about 10.

https://www.youtube.com/watch?v=HtUH9z_Oey8 The Beatles - Strawberry Fields Forever

https://www.youtube.com/watch?v=tLFL1-zX2FMNL
Paul McCartney Is Now Over 80 How He Lives Is Sad

https://www.youtube.com/watch?v=-9nfO7NwWiM
The Beatles - Live At The ABC Theatre, Blackpool, United Kingdom (August 1, 1965)

https://www.youtube.com/watch?v=XzSrShbqlz8 George Harrison & Ringo Starr - While My Guitar Gently Weeps (The Prince's Trust Rock Gala 1987)

https://www.youtube.com/watch?v=l3eN7WgLNXc Tekst en Muziek: Boudewijn de Groot Verdronken Vlinder

https://www.youtube.com/watch?v=U3X85dLO-5U Boudewijn de Groot Verdronken vlinder

The Drum Mystery in The Beatles' Most Beautiful Song | Dear Prudence https://www.youtube.com/watch?v=ptAmOYIFIx8

https://www.youtube.com/watch?v=KBZUetjx7jg George Harrison - the complete last performance

Watch ex-Beatles John Lennon and George Harrison develop OH MY LOVE- 1971 Imagine recording sessions https://www.youtube.com/watch?v=yksV7YVuqdg