It is the "official" biography of McCartney and was written "based on hundreds of hours of exclusive interviews undertaken over a period of five years", according to the back cover of the 1998 paperback edition.

[3][4] In this way, the book was an extension of McCartney's campaign to establish his legacy, particularly with regard to the Beatles' forays into the avant-garde,[5] and followed statements he had made on the subject in a 1986 interview with Rolling Stone magazine[6] and in the programme for his 1989–90 world tour.

[14] Its popularity came at the end of a year of considerable professional success for McCartney, following his knighthood in January and the favourable response afforded his album Flaming Pie.

[15] Many Years from Now attracted criticism from some readers for its focus on songwriting credits and McCartney's attribution of percentages to determine the extent of his and Lennon's respective authorship of a Lennon–McCartney composition.

Blackhurst regretted that Miles "exacerbates this distasteful trait in his subject by inserting his own mindless jibes" and found the tone both contrary to the "warmth and great personal integrity" McCartney displayed when discussing family, and unnecessary, given that the former Beatle had already won a newfound respect from contemporary listeners in the 1990s.

[20] According to author and music critic Tim Riley, the best reaction to Many Years from Now, and to McCartney's public efforts to persuade Ono to let him change the Lennon–McCartney songwriting credit for "Yesterday", came from Rolling Stone contributing editor Mim Udovitch, who wrote: "[He] makes you want to sit down and write him a letter saying, 'Dear Sir Paul: Anybody who really knows recognizes that without your superb musicianship, the Beatles could not have been.

[22][nb 1] Reviewing for Amazon.com, Entertainment Weekly critic Tim Appelo wrote: "This book is even better than A Hard Day's Write: The Stories Behind Every Beatles' Song and Revolution in the Head.

"[25] Ingham concedes that the text contains "fascinating detail" but he finds the adoption of songwriting percentages "faintly embarrassing" and "desperate", and similarly bemoans McCartney's "'I was the cool one really' justifications".

"[28] New Zealand Herald critic Graham Reid describes Many Years from Now as "a fascinating, if skewed and somewhat frustrating book" with minimal acknowledgement of Harrison and with Starr "again the invisible man".