The time I unintentionally insulted my physics teacher

What's the first dimension?
A dot or line

What's something two-dimensional?
A drawing of a square, something with no thickness

What's 3D?
A cube.  Something with length, width and height.

What's the fourth dimension?
Time.

What's the fifth dimension?
...
Actually, no, not yet;  I'll tell you later and start at the beginning of the story...

Twas the beginning of the school year and I was taking physics as my science requirement.  My best friend was in the same class, and before our seating arrangements were set we used to sit next at the same two-person table in the center of the grid of tables in the classroom.  A few months prior I had taken summer school courses on physics and calculus.  Fun indeed (sarcasm).  I had been made to learn a number of things (pun intended) over those four weeks and retained, oh, maybe 8% of it.  As luck would have it, I remembered the answer to the last question above. So I thought.


Mr. A. had just asked us the first four questions above and written the answers on the whiteboard.  I got excited when he asked us what the fifth dimension, because I remembered(!) my summer school teacher saying "The fifth dimension-- it's jerk! Jerk jerk jerk, isn't that a riot!" Simple question, simple answer, right?

Mr. A:  So the fifth dimension.  Anyone care to guess what it is?
G1: (raises hand while speaking): JRK! [it somehow came out of my mouth without the vowel]
Mr. A: (slight hesitation): ...What?
G1: Jerk. (thinks to self: Of course, it's "jerk", right?  I remember this correctly, right? I'm sure of it.  Almost sure. 93%)
Mr. A: (walking closer): What was that?
(The entire class turns to look at G1, whose face has turned into a tomato, Snow White's apple, a red warning bulb)
G1: (meekly): ...jerk? (thinks to self: Scheisse. Mierda. Merde. What-- I'm right, right?) (blacks out)

I didn't actually black out.  I think.  I don't remember what happened after that or how the subject was changed and Mr. A. got back to teaching physics.  But a split second later I could see what had transpired in his mind's eye, that he thought I was calling him a jerk.  I could see him mentally reassigning my identifier:
Kid who was late to the first class
Asian girl with the glasses
The one who called me a jerk

All's well that ends well. A week later Mr. A. told the class that he consulted his physics buddies and found out that, yes, the fifth dimension is called jerk.  He sort of sheepishly apologized for the misunderstanding, and I also sheepishly apologized for using imprecise language.  Life moved on.  I did pretty okay in that class, despite my tenuous grasp of some of the theories.  My lab group performed spectacularly in most of the labs, and I'm sure that whatever identifier he used for me changed many times.  Probably something like this:
Kid who was late to the first class
Asian girl with the glasses
The one who called me a jerk
The one who inadvertantly called me a jerk when explaining the name for the fifth dimension 
The one in the all-girl lab group that beats the smarmy boys
The one who sang along to the end-of-the-year slideshow
The one who saw me and my date when we went to see "Swan Lake"I liked my physics teacher.  For the sake of this post I'll call him Mr. A. He reminded me of a pterodactyl because he was tall and lanky and had an enormous wingspan.  (But he couldn't fly).  Beside the fact that he was a teacher, he wasn't someone to insult; he was just so darn likable and relatable.  He really enjoyed his job and tried to have his enthusiasm rub off on us hapless students.  Sometimes-- on days when we had exciting labs-- we'd get into it, but otherwise we just nodded like we understood the concepts on the first go.  But I'm getting ahead of myself again.