In kindergarden...
We learn from our teachers then the letter "e" is one of the 26 alphabets and it can be written as "E" in capitals.

In primary school...
We learn that "e" stands for elephant. And as we proceed through our primary school life, we learn that seeing the letter "e" sux as it stands for examinations (e.g PSLE).

In secondary school...
We learn that "e" represents a undefined number which approximate value = 2.72. AND, by putting a power "x" to it, it gives you beautiful curves that you have to learn to sketch.

In JC...
The small "e" have grown to a big "E"! And by adding a letter "n" on the top of it and "r=1" at the bottom, it will give you a whole series of numbers that you have to sum up.

Imagine in the future what a "e" will represent...