Kendrick Lamar released his breakthrough album good kid, m.A.A.d. city on October 22, 2012. After the release of his second album, K. Dot kept a diary so he didn't forget how he felt at the time of the album's release.
Kendrick revealed this in an interview with Rolling Stone saying, “It really came from conversations I had with Dre … Hearing him tell stories about all these moments, and how it went by like that… I didn't want to forget how I was feeling when my album dropped, or when I went back to Compton.”
“There's a lot of weird shit in there, Lot of drawings, visuals.” Kendrick says on the multiple notebooks he filled up with his thoughts.