Have you ever lodged a nail in your brain and not noticed it for 6 days?

A Breckenridge construction worker is recovering after going to the dentist for a toothache that turned out to have been caused by a 4-inch nail lodged in his skull. Patrick Lawler, 23, said he was using a nail gun on Jan. 6 when it backfired, firing a nail into a nearby piece of wood. And, unbeknownst to him, a second nail went through the roof in his mouth, and into his head -- about an inch and a half into his brain -- barely missing the back of his eye.

How, how, how do you not notice a nail lodged in your brain? Or at
least the entrance wound, you know?

From the article: "'We just thought it was a big contusion. You get
punched or something, and your eyes swell up, your jaws swell up,
whatever ... We didn't think a nail was hanging out, poking where it
shouldn't have been,' Lawler said."

So he didn't notice because he thought it was like a contusion where
he got punched... but he never got punched! If my eye and jaw was
swollen, all of a sudden, as if maybe I had been punched, and I didn't
remember getting punched, I'd think it might set off alarm bells. I'd
hope.