Cashback (2006) romantic movie explained

After a painful break up with his first girlfriend Suzy (Michelle Ryan), Ben Willis (Sean Biggerstaff), an aspiring artist, develops insomnia. To take his mind off his problem he spends his nights working at a local supermarket, where he meets colorful characters.
As the film opens, Ben begins a voiceover narration that will last pretty much all the way through and, to begin with, replaces what his angry ex-girlfriend Suzy (Michelle Ryan) said when they broke up. Whatever she was saying involves a lot of the upper front teeth overlapping the lower lip. Ben is morose at the loss of Suzy, can't sleep at night, and goes on the midnight shift at Sainsbury's (oh, the film is set in England). Then he begins to freeze time. To tell you the truth, I am not sure if he actually stops time or only fantasizes that he does; the second possibility is probably more likely.

There's a checkout clerk at the store named Sharon (Emilia Fox), who has one of those faces that looks at yours and makes friends. Ben begins to think less about Suzy. The heart of the movie involves his courtship with Sharon, which is mostly conducted by Sharon. He hangs out with a posse of male friends (the usual assorted geek, playboy and loser types) who advise him about love, a subject that for them seems largely theoretical