He told Paper magazine: "There've been a few moments where I've been really taken aback... I feel like everybody looks for some sort of approval from some form in their life, and my fans are my approval. It's a sense of achievement that you can't really explain."
The 23-year-old singer - who is dating model Gigi Hadid - was unable to dye his hair or sport facial hair during his time in One Direction because it made him look "old" so he is thrilled he can now grow a beard without getting into trouble.
He said: "Facial hair was a weird thing.
"I think it's 'cause I just looked old. And they didn't like that. [And] I always wanted a beard! I think every dude does when they're young.
"Seeing Al Pacino in 'Carlito's Way' - I needed the goatee after that. I was like, 'I wanna be Al Pacino.' I've always been obsessed with that, and I had to shave it off. I used to get a bit sad."
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Zayn's London home boasts its own pub, which he based on one of his favourite movies, Disney's Pirates of the Caribbean.
He said: "I love the [movie's] aesthetic and how well it's done.
"I feel like it's really authentic to pirate times...
"Like I know anything about 'pirate times.' I guess I just love it. I'm a big kid."
- Bang! Showbiz