system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: I've had the same cat for years and I'm certain he loves me. Why does he need to sniff me every time before he allows me to pet him? Isn't his sight enough?
gpt
You need to remember that compared to most other mammals, people are *terrible* at smelling. So while you think your smell doesn't change from day to day, to your cat, it does. When he smells you today, he notices that you've been shaking hands with different people, eating different things, handling different objects, etc. In a weird way, it's him asking about your day.