I always have a spare key on me. One in my wallet one in a magnetc hide-a-key that my trip partners know about.
The one in the wallet is for town use. The magnetic is for trips and town use.
On outdoor trips, I throw my full set of keys in the car out of site and carry a spare key (no fob) in my ziplock "wallet".
I became a true believe about spare keys when I was about 18.
Dad was always telling me to have a spare key in my wallet. Yeah..whatever Dad.
He'd always ask if I made the spare key yet. Nope Dad..
Make it yet Paul? Nope.
A few weeks later, I got a flat on my car at my after school job. No problem. Pulled out the spare tire, the jack and swapped the flat tire out. Easy peasy. Mac-n-cheesy.
Except I locked my keys in the car.
Called home. Dad brought by a spare set of keys. He did not say a word. Just handed the keys keys to me. He just looked at me with a look I've seen too often from my childhood. He then went back home.
The following day I went to the hardware store and made a spare set of car keys.