Who said it: Owen Wilson in The Royal Tenenbaums (2001)
Argument: Over something you'd forgotten about 20 minutes ago.

It's been over an hour, you're gesticulating madly about Sweden's "progressive labor model," and, worse, you're getting vehemently passionate about it. That's when you realize you have no idea what you and your friend were arguing about in the first place. Remind yourself to focus, pipe down, and start Friday back at the beginning.