Bojack and Diane are two characters who become close because they are very similar and they ‘get’ eachother, a personal understanding you don’t get with most people.
The first time they meet, Bojack gets her costume right away, despite it being so obscure and no one else understanding.
“I always tell people you’te like the not cool version of me”
Was it part of his monologue/eulogy in Free Churro? I think we had to connect dots to truly get it, but I think that’s when it was supposed to click.