You don’t have to be an expert in proofreading to know there’s a word missing in this excerpt from Yahoo! Shine:
You don’t have to be a history expert to know there’s a hyphen missing in Spanish-American War.
You don’t have to be a science expert to know that there’s a screw missing in the writer’s cranium. Radium, like other naturally occurring elements, was not invented. Except maybe by God.