Macs make it really easy to type a certain few special characters -- em-dash among them. I'm typing on a Windows laptop and I know there's alt+numpad codes but this laptop doesn't have a numpad and I can never remember those. I used to know a few many years ago, but I've forgotten all of them.

Access to a wider array of special characters is also one of the really nice things about touch keyboards on mobile or tablet. Keyboards are great for fast, accurate typing but not for going beyond the basic character set.