I think it is probably something along the lines of what Mootworm said. We used to have a hamster (back in the day) and I had a mouse when I was a kid. Well, my corn is on aspen and it drove me nuts for months bc I kept thinking It smelled like pee. It was just that I associated aspen with rodent pee smell.
Same with cypress chips. Smells kind of like a barn to me.
I have a VERY sensitive sense of smell and I have 4 reptiles in one room...no smell, promise.