The girls were just teenagers when they appeared on the American version of the 57-year-old music mogul's talent show 'The X Factor' in 2012, and admit they found it hard to adjust to being a band in the beginning, especially as they all have very different personalities.
The 'Work from Home' hitmakers are now a four piece after Camila Cabello quit the group in December last year to start a solo career.
Ally Brooke, Normani Kordei, Dinah Jane and Lauren Jauregui released Fifth Harmony's third album on Friday (25.08.17), a self-titled LP, which is their first since Camila left.
Despite dealing with the 20-year-old singer's exit and adjusting to being a foursome, the last time the girls caught up with Simon he told them that he'd never seen them so content.
In an interview with NewsWeek Europe, Normani, 21, said: I remember we had dinner with Simon at this house and he looked at us like a proud uncle. He said, 'I'm so proud of you girls. You've come such a long way. This is the first time I've seen you this happy in such a long time.' ''
The girls, who co-wrote half of their new album, feel like they've grown up a great deal and have gained more control over their music since they started out.
And the group insist they owe their development to their Syco label boss for putting all of his faith in them after they proved they can learn to accept each other's differences.
Normani continued: ''Simon gained trust in us. We were young but we also had different personalities. And, to be completely honest, when you get into a girl group, it can be confusing because we all like different things, we all like different genres of music. But we've grown into our own. We're women now, we're not afraid to stand up for what we believe in and the things we want to talk about in our music.''
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