You really don't. At least first hand. To sit across from someone you've been married to for 5.5 years and say, yes, I'm really done. To have the therapist ask about best and worst moments, things we'll miss and not miss, things we've learned and regret. And have to listen and repeat and absorb. And to hear that he thinks he finally understands, and wanting so badly to say, ok, good, then we can move forward, but having for the best of oneself to say it's too fucking late - we both tried our best and I for one cannot try any more. To not sleep, and walk in the early morning as the birds are waking up and realize you are walking alone, and will be for a while.
Seems my purpose in life is to prepare men to be better partners in their next relationships.