Not near as many as when I was a married to a pack rat with 6 old cars and trucks, a rented storage building, a farm with a barn and outbuildings used for storage, and two post office boxes. Funny thing was, the house where we lived didn't have functional locks so when we would go away we would deadbolt the doors, leave a window unlocked, and crawl through it when we got home!

And that's the truth!

Now, for personal use, I have a house, shed and car key, with a spare for each stored in a key cache under a rock in the yard. I also work in two clinics and have a private practice, and each of those sites require 2 keys - one to enter the building, and one to enter my office.

And I also have a key to my parent's house....somewhere.