You can often tell someone's age by whether or not they know analogies in this format. It used to be a staple of standardized testing on logical deduction.
A : B :: C : D
Is read as
A is to B as C is to D. The reader is meant to understand the relationship between A and B and how it's similar to the relationship between C and D.
An easy one might be,
basketball : hoop :: hockey puck : net
But they can get quite challenging. And with multiple choice answers present in standardized testing, you often have to understand the complex relationships between many abstract concepts, and evaluate that the abstractions are of a similar type or degree.
They're actually kind of fun.
Here's an example taken from [1] (the source also has excellent discussion as to why they were removed) :
PALTRY : SIGNIFICANCE ::
A. redundant : discussion
B. austere : landscape
C. opulent : wealth
D. oblique : familiarity
E. banal : originality
For what it's worth I'm a 25-year-old Australian who never encountered this specific syntax in schooling (it was always phrased "as <x> is to what?"), but am still very familiar with it from general interactions online.
It's probably just a matter of how strongly your immediate social circle feels about formal logic.
As one data point, we never did these sort of analogy puzzles in school in Finland (but we don't have standardized multiple-choice testing either). I'm only familiar with the concept and format as a part of the general anglosphere meme complex that you naturally get exposed to if you spend time on the internet.
bacterium : animal :: raspberry pi : kubernetes cluster