It's funny, for years my list was keys, wallet, and phone, and of those it's the keys that go back the furthest. I had a key to my parents house when I was a young teen, and I've always carried keys with me since (I'm in my 60s now). I sold my house a couple months ago, and I've been living in a hotel until I close on a condo, and it feels so strange not to own any keys now, just the key card for the hotel.