Just because ... doesn't mean ...

We know and, or, but are conjunctions. If a conjunction is at the head of a sentence or clause, this clause cannot be used as the subject or object of a sentence. It is wrong to say "And he is young is interesting". Instead, say "the fact that he is young is interesting".

But there is one exception in English, the "Just because ... doesn't mean ..." construct. For example, "Just because it works doesn't mean it works well". The sentence is completely acceptable and makes clear sense. You could rewrite it as "The fact that it works doesn't mean it works well", but that's unnecessary and, in fact, it would sound affected except in formal writing. What about the grammar, though? Can we say that "Just because ..." serves as the subject of the sentence? If you ask AI's, they will say Yes. In other words, a clause serving as a subject cannot begin with "because" but *can* begin with "just because", as long as the predicate is "does not mean". This rule is so restrictive that we may as well say it is made just for this specific sentence structure.

"Just because ... doesn't mean ..." is used in everyday English. It has entered writing, even in non-fiction books. But in seriously formal writing, this construct should be avoided, as experts have suggested. The reason, I suspect, may have to do with its unusual grammar, as said before: a clause introduced by a conjunction cannot serve as the subject (or object) of a sentence, generally speaking.

How to remember "mean", "median", "mode"

Mean (the average value, 均值)
Median (the middle value, 中位数)
Mode (the most common value, 众数)

The three words are easy in Chinese because the the Chinese characters tell you what the terms mean. But the meanings of the English words may not be so obvious. It's worth thinking of a way to help remember them.

English 'mean' and 'median' are from the same Latin word 'medianus'. When it entered Old French, it lost the consonant 'd' (this is a regular change as it's between two unstressed vowels) and eventually entered English as 'mean', as early as the 14th century. This meaning was taken by the common people. Later, Latin 'medianus' entered French as a learned word, i.e. taken by the church scribes, who tried to preserve the original Latin pronunciation, so the 'd' was not omitted (even though the people on the street did not pronounce it). It's probably safe to say that the more popular or vulgar or low-status word 'mean' takes the more general meaning ("average value"), and the more learned or high-status word 'median' takes a more specialized meaning such as defined by mathematicians or statisticians as "middle value". As to 'mode', it's an entirely different word. Think of 'à la mode' or "in the fashion". What is in fashion is the most common. So 'mode' denotes the value that occurs the most in a set.

In general, it is not right to invoke etymology to explain the meaning especially a subtle one of a modern word in modern usage. That's considered an etymological fallacy. But in this case, it makes sense to use etymology to explain why 'mean' takes a more general sense while 'median' takes a more specialized one.