Lyric discussion by whimsically.aberrant 

It's definitely about a potential break up. But to put a different spin on it... Could it be about Page and Robertson themselves? Not a couple (clearly) but the band splitting up? I know they've had a very tumultuous relationship pretty much ever since they were kids, some very big highs as well as some tough lows. My guess is that the trouble that caused the final split has been a long time coming. I can totally picture the two men laying on the floor going back and forth reminiscing to when they literally had nothing.

"Maybe you'll forgive the things that I forgot." Stay. "Maybe you're forgetting all the times we fought." Split. "Maybe we should divvy up the things we bought."Split. "But maybe" Split. "But maybe not" Stay.

Those heart wrenching "breakups" happen in all kinds of relationships with shared emotional history. They are financially intertwined. They literally grew up together. I imagine the first "pretty soon" section from Page's point of view and the second "pretty soon" from Robertsons.