I'm going to be picky for a second. Pop open any Calculus book and you'll find a table of integrals:

For whatever reason, the natural base is always called out as unique and special. If you look at the equivalent derivative table you'll see it gets a call out from a generic exponential. But why do this? The natural base *e* is just a number, albeit irrational. If you integrate a base *e* exponential using the generic rule, you get *e*^x / ln *e* which reduces to *e*^x.

Calling it out as something special with a different rule loses site of base *e* being one of many possible bases for exponential functions. That somehow *e* isn't just a number. The same hang up exists with π whether you've noticed it or not. And it furthers the love of special cases: specific steps must be remembered for almost everything, when really you've missed an opportunity to show algebra in action.