In 1995, Chris Brander (RYAN REYNOLDS) was an overweight but sweet dweeb who was in love with the beautiful Jamie Palamino (AMY SMART), his best friend who loved him...like a brother. When Chris' true feelings were revealed and made fun of a party where fellow nerd Dusty (CHRIS KLEIN) also tried to hit on Jamie, Chris raced away, vowing never to return.
Ten years later, Chris is a successful record executive in Los Angeles who's now trim and has no problems getting any girl he wants. That includes the untalented but extremely successful pop singer Samantha James (ANNA FARIS). Chris once had a fling with her, but his boss, KC (STEPHEN ROOT), wants him to get her business and so Chris reluctantly accompanies her on a cross-country flight.
When it's unexpectedly grounded, they end up not far from Trenton, NJ where Chris' mom, Carol (JULIE HAGERTY), and brother, Mike (CHRISTOPHER MARQUETTE), still live. Chris can't stand being around the demanding and dimwitted Samantha, but enjoys meeting up with some of his former friends, including Jamie who now works as a waitress at a local bar.
Despite now being a confident and successful man, he reverts to his old, nerdy ways in her presence. While having to deal with Samantha and all of her accompanying baggage, Chris then goes through various approaches of trying to impress Jamie and finally tell her how he truly feels about her, unaware of the comedic obstacles and complications that will get in his way.