"[3] In the 'Casual Conversation with Jarvis Cocker at LIPA' (25 July 2018), McCartney said that in his opinion John Lennon would like this song.

"I Don't Know" was also engineered by Steve Orchard, Alex Pasco, Billy Bush, Julian Burg and Greg Kurstin.

On 11 October 2018, the official Paul McCartney website announced that the exclusive version of the double A-side single would be released as part of Record Store Day.

In The Guardian, Alexis Petridis wrote that "I Don't Know" is "impossibly sumptuous" and "shows [McCartney's] extraordinary melodic facility is completely intact".

[10] A review in The Times praised its "beautiful piano melody" and compared it to McCartney's early solo work—"equally breezy and sad".