The context: While "So What" will bring you up, "I Don't Believe You" will break your heart. Pink also wrote this in 2008, when she and Carey split up. She notably wears her real wedding dress in the video.
In her words: Pink revealed to the Los Angeles Times that she played this track for Carey during their separation. "It's the most heartbreaking song I've ever written. I've never been there before. I've never been in that much pain before as I was that night. That was tough, that was the darkest." In a post-recording interview, Pink added that while it was initially hard for her to listen to, she loves the song: "It's the vulnerable and weak side of me that I don't let out very often."
Most revealing lyrics: "No I don't believe you / When you say don't come around here no more / I won't remind you / You said we wouldn't be apart / No I don't believe you / When you say you don't need me anymore / So don't pretend to / Not love me at all."