But sorrow is unreliable in that way. When people don't share it there's a good chance that it will drive them apart instead.

You're not scared. You're just grieving. No one tells you humans that your sorrow feels like fear.

People in the real world always say, when something terrible happens, that the sadness and loss and aching pain of the heart will “lessen as time passes,” but it isn’t true. Sorrow and loss are constant, but if we all had to go through our whole lives carrying them the whole time, we wouldn’t be able to stand it. The sadness would paralyze us. So in the end we just pack it into bags and find somewhere to leave it.

Maybe their sorrow over children that never came should have brought the two men closer. But sorrow is unreliable in that way. When people don't share it there's a good chance that it will drive them apart instead.