Especially when we're reading.
And then we expect normal readers to think as much as we do.
"It's so obvious!" we cry when we figure out what's going to happen next three chapters before it does.
It's not that obvious. We just know we would have done. or at least considered, -the exact same thing.-
We then turn around and think too hard about our writing. We write things to purposely obscure our meanings and our aims because we don't want to be too obvious. All we really end up doing in this situation is make our writing unapproachable. . . and really, pretty bad.
This short post has been a public service announcement: stop thinking so hard, because your readers certainly aren't.