That reminds me of how things I considered mandatory previously (carrying small notebook + pen). They weren't mandatory, and most people won't do the manual thing. Don't get me wrong, you'd keep important addresses, say, your grandma out of town. And of course, professionally. But by and large, people just expected you to be in the phone book and vice versa. It also meant calling someone you knew without explicitly being given their number wasn't a faux pas. Now that I think about it, a lot of things were easier. Sigh