Episode: 4x02 (Season 4 Episode 02) Name: Things I Forgot at Birth Originally Aired: Oct. 04, 2006 Plot: Nathan, Cooper, and Rachel continue to deal with the aftermath of the car accident, each of them struggling with their emotions in their own way. Meanwhile, Brooke celebrates her 18th birthday alone due to her issues with both Lucas and Peyton. Elsewhere, Lucas and Karen come to terms with Karen's pregnancy without Keith, and Deb's addiction has explosive results at the cafe.