Don't you think people don't really understand until they've gone through the same thing?

I don't know what it means to lose a child, nor do I ever want to find out. However, if a person, tells me any of the things that you've mentioned above, the least I can do is "show some empathy, sympathy and compion" and I will make sure, the words that come out of my mouth, will make that person feel any better than before.