I’d been telling my mates that I was going to be a professional musician since I was 14. When I was a captain in the British army in Kosovo, I had a guitar strapped to my tank. After I left the military, I did some demos for EMI and outside afterwards I lost my balance on my motorbike and smashed the guitar that had survived a war zone. Everyone was laughing. Needless to say, I didn’t get signed by EMI.

One day I was on the underground in London and saw an ex-girlfriend with her new boyfriend. Our eyes met, but we just walked past each other, and I went home and wrote the words to You’re Beautiful in two minutes. I went to see my songwriter friend Sacha Skarbek in Los Angeles, and, with Amanda Ghost as a co-writer, we finished the song. It’s always been portrayed as romantic, but it’s actually a bit creepy. It’s about a guy (me) who’s high and stalking someone else’s girlfriend on the subway. But everyone has those moments where you wonder: “What if I’d said something?”

I played it on the 25th floor of a hotel at the South by Southwest festival in Texas. Linda Perry [the singer, songwriter and record producer] was there and said she wanted to sign me to her new label. The label asked me to remove the words “fucking high” from You’re Beautiful. I tried “particularly high”, “especially high”! Eventually I sang “flying high” on the radio edit but wanted the released version left as it was. I told them: “I was fucking high!”

The song has a false start. I sing “my life is brilliant” twice, which is my little joke, but I think in my elated state, from whatever concoction I might have taken at the time, life did seem really brilliant. The tube certainly looked very colourful.

For the video I agreed to jump off a cliff in Mallorca. By the time I got there, I realised I’d made a terrible mistake but it was too late to back out. They had divers in the water in case I knocked myself unconscious. I had to jump twice because the first take wasn’t right, and I ended up with a split lip. It hurt, but it made a great video.

I had no idea the song would be such a big hit, and it scared me at first. I thought I’d just be a musician putting out music. The song [released in 2004] became so ubiquitous that it started to irritate people, but I’m still proud of it and I love my job. I sang it at Elton John and David Furnish’s civil ceremony and I’m about to start my sixth world tour. Without You’re Beautiful, it’d be a tour of north London.

Mobbed … James Blunt crowd surfs at the Invictus Games opening ceremony in London, 2014. Photograph: Chris Jackson/Getty Images

Tom Rothrock, producer

I watched South by Southwest on the internet and saw James. He sounded pretty interesting, but then I promptly forgot all about him. A few days later I heard that Linda Perry was looking for me to produce a new artist. She’d just had a couple of big hits with Pink and Christina Aguilera. I figured that if she was crazy enough to sign a new artist from SXSW I might be crazy enough to record him.

James’s demo tape was all over the place, but You’re Beautiful and Goodbye My Lover were on there. We had a lunch meeting and I didn’t know what he looked like, but when he walked in with his manager I immediately felt a connection and thought: “That’s gotta be him.” I visited him in his flat in London and he played me the songs on the instruments he wrote them on, to get the dodgy demos out of my mind. We did a lot of the recording at my home studio, which was unusual back then, but the budget was modest.

One day we were doing the strings with a quartet and something wasn’t right. Strings are expensive, so I called the arranger in to see if we could work out why. The strings needed a tweak but it was the first time I’d been able to step back and just listen and I just got that chill you get sometimes when you know a song is special or is going to connect very, very widely.

A few months later, You’re Beautiful had blown the heck up and he was doing two nights at Shepherd’s Bush Empire. We went to a pub near the venue and outside we got mobbed. I said: “James, remember a few months ago, we were having a beer and nobody knew who you were?” And he said: “Yeah, wasn’t it great?!”