> One of which is 'e', where the history and its origins will help you understand why it behaves the way it does. Without this context, 'e' is just some arbitra

> One of which is 'e', where the history and its origins will help you understand why it behaves the way it does. Without this context, 'e' is just some arbitrary number that you have to memorize. What? I have no idea about the history of `e` (though I have a good idea who "found" it) but it is incredibly important and it's pretty easy to explain why -- if you have a dollar in the bank, earning interest at an instantaneous rate of 100% per annum, but continuously compounded, `e` is the amount of money you'd have at the end of one year. Very, very simple. When the rate of change is equal to the quantity itself, `e` is the thing you exponentiate.