Anneintherain gave some excellent insight. I would add that some divorces can cause as much grief as a death. Everyone handles it differently depending on how much grieving occurred before the legalities, the causes, personality types, etc.
Although the guy I am involved with ultimately chose to separate from his wife, he never believed that things couldn't be fixed through open communication and working together to make repairs. The blow came when his wife, who stated she didn't want the divorce, also had no interest in communicating or doing anything to make repairs. He is a very logical person, but his grief has been rather intense.
As Anneintherain pointed out, I try to take my cues from him. When he wants to talk about it, we discuss it. And when he changes the subject, I let it drop. Oftentimes there is nothing logically left to understand, it is just sorting through the emotions, and that takes time and repeat conversations.