Sometimes, terminology is terminology for a reason. "Dumbing Down" language to explain things can be difficult without causing potentially grand misunderstanding.

One of the hard thing to do when making a presentation.
Sometimes you just expect those who came to your presentation to at least have a little bit of knowledge about the subject.

Even in English is still hard to remember all those stuffs

Kryptik said:

Sometimes, terminology is terminology for a reason. "Dumbing Down" language to explain things can be difficult without causing potentially grand misunderstanding.

But to paraphrase Feynman, if you can't explain chemistry to a bricklayer, then you don't really understand chemistry at all.

'though yeah, this is a common problem with engineers and others who work in applied sciences (or other fields), since they were thought the specific terminology and how to apply it in their job. The theory behind it? Eh, it's in the textbook somewhere, but it's not going to come up in exams or on the job anyway, so...

(Okay, sometimes you are asked to "give a definition", but that usually ends up being memorized ad verbatim from the textbook, or heaven forbid, the lecture slides)

Theorists? Shouldn't be a problem, but sadly it is, due to the mountains of literature you have to sift through. Somebody came up with the term first, and it's buried under a mountain of other jargon, so...

And let's not get started on ZFC set theory. Or other branches of 'pure' math, for that matter.

(Also, Feynman, like most geniuses, tends to overestimate the intelligence of everyone else.)