When Delilah wakes up one morning in a bed that's not her own, she experiences the biggest regret of her life. Not only did she have drunken sex with her disgusting former boss Roger (who fired her the day before) but in doing so she hit her self-imposed 'number limit'; she's had sex with twenty men.

What's your number? no, not your phone number. Your number. You know what I'm talking about, don't you? Nope, wrong again. Not your age. Not your salary either. Your 'number', silly. Do I have to spell it out for you? How many men have you...you know...done it with?
When Delilah wakes up one morning in a bed that's not her own, she experiences the biggest regret of her life. Not only did she have drunken sex with her disgusting former boss Roger (who fired her the day before) but in doing so she hit her self-imposed 'number limit'; she's had sex with twenty men. The one spot she had left was supposed to be saved for the man she would marry. Refusing to give up on her number limit, , she goes and tracks down all the men she's ever slept with. Somewhere amongst them must be The Man, only she didn't realise it at the time...
She embarks on her stalker-like search amongst the twenty former lovers, which involves walking the dog (first having to buy a dog, of course), enrolling in a cookery course, joining a gym, visiting a jail (he gets out in a month - it was worth a shot) and even checking into rehab. And in the end, of course, Delilah comes to realise that numbers don't matter and that true love comes when you're open and ready for it.