Cursive
Millennials were definitely the last generation to be taught cursive. Boomers (and some Gen-X) only write in cursive. Those birthday cards are sweet but so dang hard to read!
Using a Phonebook
You can Google anything you want these days but Boomers will never get rid of their phonebook. They might not even use the phonebook and they could very well be savvy with Google, but they still have one stuffed away somewhere. You never know when you're going to need it, okay?