To me, keys denote responsibility. I never needed any when I was a kid. My mother was at home when I came in from school, and if she wasn't, she left one for me under the doormat. When I got to college, you knew you were really a hotshot in the Theatre Department if you had the key to something in the building.
In my former life in California, I was laden with keys. I had keys to my house, keys to my partner's house, keys to my car and keys to my workplace. Now I live in New York. My office building has 24 hour security and no one needs a key. My housemates keep the back door unlocked all day until all of us are home at night. I do have a house key, but I don't carry it. My California house is rented out and my car has been in California, mostly in the repair shop, since I've been gone. It occurred to me after I'd been there about two weeks. No keys. No car to park, no dog to walk, no responsibility. I wake up and someone's already made coffee. I come home from work and someone's made dinner.
Well that's all over, now. I have flown home and we are now going to drive back to New York to bring the dog and set up the new apartment. No more keyless life. My keys are on my belt, as they have been for most of the last thirty years. It was a nice break, but now it's back to responsibility.