Soul Kitchen, a fun 2009 German film directed by Fatih Akin that demonstrates what can happen when you make all the wrong choices, but end up learning something in the process. Screenwriter Adam Bousdoukos based the story on his own experiences as the owner of a Greek tavern named Taverna, where Akın was a regular customer.
This is the perfect movie to watch if you've been ruminating on the past, thinking about mistakes and how you'd do so many things differently now. You'll feel so much better about yourself -- no one can make as many bone-headed mistakes as these guys -- and you'll also see that no matter how many bad choices you make, it's still a learning experience!
If you'd like to see more of Fatih Akin's work, I also recommend his 2007 drama of missed connections juxtaposed against nexpected ones The Edge of Heaven with the luminous talents of Hanna Schygulla and Baki Davrak.