Why is this so common but people are so oblivious?

So apparently miscarriage is insanely common and we just don’t know because people don’t always share it... ok, got it.

But if it’s so common, why don’t people know how to react/be understanding, etc?

My dad died of cancer when I was in second grade and people didn’t know what to say cuz kids aren’t supposed to lose their parents that young. Ok, but I was able to deal with it and move on and the mention of him doesn’t make me a wreck.

If miscarriage is so common, why do I feel like I’m trying to cover up a mental illness? Why do I feel like some of the people who knew about it act as if that baby never existed? Why don’t people understand that this pregnancy has turned me into a wreck because of what I know can happen?