@jeeprs,
jeeprs wrote:I can never understand why a 'meme' is not simply a fancy way of saying 'idea'.
It's not an idea. It's a completely different formation.
"lol" is a meme, not an idea. Memes are successful when the are propagated, the utility of which is discovered later.
Memes aren't just language either. If it was, we might just refer to them as neologisms. Here's another meme:

The peace sign gesture.
Similarly... if you change the direction of your hand it becomes the victory sign (the meaning of which escapes many...)
memes aren't ideas
if I want to express frustration, might type out...
a;oifna'ociena;coien;cainf;a
...by randomly hitting keys. Now frustration is an idea, but frantic key pressing is a meme. Even if I hit different keys...
a;oinao;in;odfina;fokeofjdewnwnw
... the idea is the same, while the meme itself has mutated.
A
R
T