What is something debunked as propaganda that is still widely believed? #propaganda #conspiracy

What is something debunked as propaganda that is still widely believed?
That propaganda is necessarily misleading or false. Propaganda is simply a method of directional persuasion. Can it be false or misleading? Without question. But it can also simultaneously be factually unimpeachable and rhetorically suggestive.
Catherine the great dying from flocking a horse.
That napoleon was short
That cracking your knuckles causes arthritis. Science nerd Donald Unger cracked the knuckles on his left hand only for 50 years, no arthritis. Suck it Nana.
That plastics are easily recyclable, and that MSG is bad for you.
The rampant tampering of Halloween candy.
Is it weird that I still believe that rumor we all spread in middle school that Marilyn Manson had two ribs removed so he could suck his own dick?
Butter helps a burn
That MSG is bad for you.
That diamonds are rare and expensive to obtain.
That swimming within 30 minutes of eating will cause cramps.
That eating fat makes you fat or is bad for you
That vaccines causes autism. Fuck Andrew Wakefield - he should’ve been jailed for his fraudulent study.
…*sorts comments by controversial*
That a majority of people imprisoned in the US are violent offenders. It doesn’t even constitute 10%.
You need a big diamond to propose.
That penis inspection days at school were mandatory and you'd get expelled if you didn't go.
The flocking litter boxes in school bathrooms.
That video games cause violence
That “nobody wants to work”
MSG