These aren't well known in the fandom but the 4 freestyles namjoon released shortly before debut are some of the rawest and most honest he ever did. You can really see how much bangtan means to him

"When I first came here, I was alone
Maybe because of that, I was so lonely
Yeah, I’m the first male trainee for Big Hit
But I didn’t have a buddy anywhere
After locking myself in a lonely empty room at a young age
These kids called 'members' came"

links to freestyle 2 (first tweet)

freestyle 3 (second tweet)