Don't get perturbed by the title. Simple maths to understand this is more than enough. I was in a daze in Dr. Kosbar's class listening to signal space representation of signals and other stuff. And then, there was a mention of Maths. He came up with a good one!
A function is travelling in a dark alley with a lot of money. An operator comes up to the function and asks the function to give all the money. The function refuses to give the money. So the operator says that if the function doesn't give the money, it will differentiate it. The function is not perturbed. It says "Hahaha! I am e ^x(e to the power of x)". The operator is not perplexed. Guess why?
The operator says: I am d/dy!!!!
What do you say for that???