Years & Years wrote this song for the Baz Luhrmann-directed short film, The Secret Life Of Flowers. The Moulin Rouge director created the fantastical love story to launch H&M's collection with fashion designer Erdem Moralioglu. Speaking on the collaboration, Years & Years frontman Olly Alexander said:
"It was a really wonderful experience working with Baz, he's so passionate about every detail, and I was really excited to be part of something so creative. Plus, I've always been a fan of Erdem. The song is about falling head over heels for somebody and it totally up-ends everything you thought you knew about yourself."
Olly Alexander said regarding the tune's meaning: "The song is about falling head over heels for somebody and it totally upends everything you thought you knew about yourself."
When Olly Alexander wrote the song, he had been single for two years but he drew on the memories of falling in love with Clean Bandit's Neil Amin-Smith, whom he dated for nearly a year in 2015. The singer told The Sun: "Hypnotised is about that initial stage of a relationship. I wanted to write about that feeling of being intoxicated in the romance of it. And I do sometimes wonder if I am ever going to fall in love with someone again."