Gallagher claims that he was drunk while writing it, and parts of the song were inspired by walking while listening to a Walkman ("walking to the sound of my favourite tune") and using cocaine -- ("all your dreams are made/when you're chained to the mirror and the razor blade"), since razors are often used to cut cocaine into lines on a mirror, from which they are then snorted. It has been suggested that the song is about drug addiction in general ("need a little time to wake up/need a little time to rest your mind/you know you should so I guess you might as well").

The line "Tomorrow never knows what it doesn't know too soon" seems to reference The Beatles' song "Tomorrow Never Knows", though Gallagher claims to have completely forgotten why he felt it was relevant to the song.

According to Gallagher in a 2005 interview, the song originated from an early song called "Blue." The lyrics were something along the lines of:

"I live my life in blue, There's nothing anyone can do"

...which he decreed to be "Fucking awful." There was also an early song written by Noel, entitled "The Mirror And The Razorblade", where the first verse went:

"The mirror and the razorblade, If you live round here it's where your dreams are made, There's no beach, no bucket and spade, For me"

...the second verse went:

"Rainy Monday afternoon, All you need is your favourite tune, The end of the day can't come too soon, For me"

...and the third verse went:

"Remember what we used to say, The dreams we'd dream and the games we'd [play], It doesn't matter anymore anyway, To me"

The main riff of the song bears a close resemblance to R.E.M.'s "The One I Love". Oasis' song is much better.

In October 2005, a remix of the song was released on the soundtrack to the movie Goal!. It was done by Don't Believe the Truth producer Dave Sardy.

The song is included on Oasis' compilation album Stop The Clocks.

On the album, the song segues into the 40-second untitled track, which in turn segues into "Champagne Supernova".

Morning Glory is a US-exclusive promotional single by the British band Jamiroquai. The single never had any official release, and was only released as a promotional CD, as mentioned before. A song from the debut album of the band, If I Like It I Do It had a similar fate to this song's one. As a collectible, the single is considered to be only a one of the many holy grails of collecting by most fans. Mint examples have exchanged hands on eBay for $1000 or more.

The harp introduction to the song was sampled by Missy Elliott in the interlude "Bite Our Style".