I recall that learning that lim(1 - 1/n)^n with n->inf is 1/e, was one of the first things learned in Calculus. I think we even briefly touched this in highschool.
It would be e if there had been a + sign in the parens, but with a - it is, in fact, 1/e. (1-1/n) is always less than 1; multiplying a bunch of factors less than 1 can't possibly* give you 2.something.