How stoned was Seth Rogen on Late Night with David Letterman last night? "Not very!" F*ck yeah. 

Rogan and Letterman, who hasn't smoked for 30 years, ended up having a completely fascinating discussion about smoking up. Turns out Rogan offered to smoke up Barbra Streisand while working on their new movie, "The Guilt Trip." She wasn't having it.

Is it just me or is this exactly what talking to your parents or grandparents about weed is like?