The actor - who has played the boy wizard in every film in the series since he was just 11 - finished shooting the final scenes for 'Harry Potter and the Deathly Hallows: Part II' in June and was an emotional wreck when he was saying his goodbyes to his cast mates and the crew.
He said: "We were all in bits. I've never seen Rupert Grint cry in my life but it was really emotional. When I saw him cry, it made me cry more. It's come to stand for my childhood, which I've said goodbye to. That innocent small boy has gone."
Although he and his two main co-stars Rupert Grint and Emma Watson have grown up together, Daniel doesn't believe the trio have changed that much as people.
The 21-year-old star added to Britain's OK! magazine: "Rupert has obviously got a much bigger car collection than when we started! Obviously, Rupert and myself have both changed through the series, because at the beginning, Rupert was really, really chatty, you couldn't shut him up. He's got quieter as the series has gone on, and while he's got quieter I've got louder!
"Physically, me and Rupert look totally different, whereas Emma, I think, kind of almost looks exactly the same as when she started, in terms of her face. Other than that it's kind of hard to say how we've changed, other than just the fact we've grown up."