Yes, this is indeed something I do. XD
Honestly, I am not sure where this started, but I can say my interest in keys has been a thing since I was a very young kid. My family used to joke that I was a sort of magpie as as seeing a set of keys in someones hand, or hearing them jingle in a persons pocket always caught my attention, and if I step into someones house, they can sometimes be one of the first things I notice, whether they are stuck in the door, or in a little catchall bowl or hanging up on a key holder. I've always had a weird curiosity for them.
I have learned that a person's set of house keys can also act as a storyteller of sorts about the person, similar to the clothing they wear or jewellery. For instance, what car they drive, from the car key. Oftentimes I may even guesstimate what model of car they drive, as well as looking at their many keyrings (or key charms) if they have any. A little Mickey Mouse-themed keyring often suggests they went to Disneyland, or they know someone who did. A little acrylic photo keyring with an image of thier pets or family, as well as other charms. Maybe it can be a charm with thier name on it or thier initial. They can often be good conversation starters.
They have also played a role in my life in other ways, too. My Gran has told me the same story many times of how giving me her keys effectively calmed me down from the freak-out of getting a flu vaccine. Apparently one of my very first words was literally "ignition key". As a child, holding someone elses keys, especially when they were family or someone I knew well, was comforting. They also helped me in getting diagnosed as being on the autistic spectrum. Initially, I was proposed to be diagnosed with Dispraxia, as I wasnt too good with co-ordinating my hands. That was no sooner put to bed when my Gran gave me her house keys and instructed me to take them part and put them back together, which I did, and back in the original order too. To this day though, I have only been diagnosed as "on the spectrum", with no specific diagnosis.
Pictured here is effectively a sample of what at one point was my car key collection. I had a bunch of old door keys and stuff too, but car keys were my go-to and still are. This collection has since outgrown this tiny little Coca-Cola branded tin.