truth behind our reasoning

Diane's monologue in Bojack Horseman S5E2 broke my heart:

.... reason number 10 you go to Vietnam - because you got to leave to come home. 

Mr Peanutbutter: Diane, I have something I need to tell you. I'm seeing someone, romantically, and it's not you. This probably isn't the best way to say it.  

but none of those reasons are why you actually went to Vietnam. The real reason you go to Vietnam, is because you accidentally see your soon-to-be ex-husband kiss someone else. At first you think, "Oh, it's a fling. Whatever, they're drunk, it's a party." But then he puts his hand at the small of her back, exactly the way he used to do to you. It means 'I've got you' and when he did it to you it made you feel safe. And you realize, he will never do that to you again.
And it breaks your heart again after your heart is so broken that you thought it could never get any more broken. You thought it was safe, but it still somehow finds a new way to break. Because even though you're the one who asked for this, now that you've got it you are completely adrift. With no compass, or map, or sense of where to go, or what to do. So you go to Vietnam.
You think you might find community, a connection to something bigger, but.. you don't. In fact, you feel even more alone than you were before you left. But.. you survive. You learn that you can survive being alone. 

Diane: I'm really happy for you, Mr Peanutbutter.