Songfacts®:

• This Grime-Pop paean to young love features Stryder's fellow Londoners, the pop trio N-Dubz. It originally only featured Dappy, but Tulisa and Fazer recorded extra vocals so the track could be included on N-Dubz's Against All Odds album.
• This song features a string sample of "The Last Time" as performed by The Andrew Oldham Orchestra. The same sample was previously utilised by The Verve on their 1997 hit "Bittersweet Symphony."
• When this topped the UK singles chart, we thought Stryder may have became the shortest ever adult male to reach #1. But, at 5 feet, 5 inches, the East London MC dwarfs the tiniest man to reach the summit, the 5 foot, 2 inch Prince.
• This aptly named song become the first UK #1 single to reference the chart position in its title. The two acts who previously had come closest to achieving this feat were The Tremeloes with "(Call Me) Number One" and S Club 7 with "You're My Number One," which both stalled at #2. Several chart-topping songs have included the phrase "number one" in their lyrics, including in 1980 Blondie's "The Tide is High" and the tune that succeeded it at the summit, Abba's Super Trouper."
• The Daily Mirror August 14, 2009 asked Styder whether the title of this chart-topping song was an example of positive thinking as self-fulfilling prophecy? He replied: "Nah, it was as simple as thinking of the phrase 'number one.'. At first we had 'you're the one', but in the studio I thought 'number one' was better."
• Stryder told The Lancashire Evening Post that his favorite collaboration to date was with N-Dubz on this track, due to he and the N-Dubz frontman getting on so well. He grinned: "It's just Dappy really. I met them a few years back at the first MOBOs I went to. I was just speaking to him really, like, yeah, we need to do something... and then we was all busy and then no one ever had time but then it just came about that our managers wanted to do it and our A&R and everyone got on it. Then I spoke to Dappy. It wasn't even nothing overplanned, we just went in the studio and we was cool from before anyway and we just started writing and working on the track. We was only in there for like an hour actually writing the song, yeah man, it just came together that quick."