The phrase refers to an anti-drug ad campaign that revolved around showing pictures of people in ruin with the phrase "Meth: not even once", general implication being that if you do meth even a single time it will suck you in and ruin your life.
The ad took off in the internet and was re-purposed, replacing "meth" with other things (X: not even once), generally meaning that the author of the image thinks that practicing X will lead to no good.
Someone seeing a woman's poorly-thought out tweet concerning a hot button political issue:
- Woman in politics: not even once.
Comes from russian word "Manyamirok" (Манямирок) which means Manya's little world. Manya (Маня) is a feminine russian name, on its own used online in reference to effeminate men, practice comes from a popular soviet film about prisoners Bespredel (Lawlessness), 1989. The phrase manyaworld is generally used on international social media platforms by russian speaking users when their opponent is speaking about political/social issues but actually has no clue how shitty the real world is.
A person mockingly quoting their opponent: >No! In my manyaworld repressing dissent is not needed to consolidate power after the civil war.!