Have you ever found yourself attracted to someone that you once found completely repulsive? How I Met Your Mother can explain—it's called "The Mermaid Theory." Inside, Barney explains the history and Marshall narrowly avoids the issue with Robin.

Additionally, we discovered that Jason Segel kind of looks like Zach Galifianakis with a burly beard and that Robin is still hot—even when she's wearing a manatee costume.

[There was a video here]