Like A Nail In The Head Edit Meaning

1.

An analogy for obvious. This was originally coined by a pharmacy professor at the UT Health Science Center at San Antonio. The professor was referring to Phineas Gage, a 19th century railroad worker, who suffered a freak accident when an explosion catapulted a large piece of iron through his skull and into his frontal lobes. An injury that was anything but subtle.

Professor: "what's an antibiotic used for?"

Student Bob: "Uh, there is an inhibitory, Uh, upregulation and, Uh half life ..."

Professor: "An antibiotic kills bacteria. Bob, the answer was like a nail in the head and somehow you completely missed it"

See nail, head, obvious, railroad