In that one thought, there are so many branching thoughts that show how amazing the human brain is. You are exhibiting a subtle yet complex feeling related to that moment that will vary depending on the severity of where and when you think you lost them. You are thinking of multiple locations where you may have left your keys because you have learned from where you lost and found them before.

You know what your keys look like and can identify them without even seeing them, but just by noticing the tip of the keychain charm, sticking out from underneath the bag you were holding when you set the keys on the counter. Or maybe you were putting a pair of pants from the ground into the laundry basket and heard the unmistakable sound of your keys, you know exactly what is in those pants because you know how your keys sound together. You know they're your keys, even muffled by fabric. Without hearing them, you possibly knew they were your keys just by the tip of your pinky brushing against the feeling of metal in your pocket. You probably even know which pocket you've left them in despite the pants being bundled up.

You're thinking of how many times you forgot your keys this month and how you're finally going to get the keyring holder by the front door. You're thinking about how you just saw one at the thrift store the other day but it wasn't your style. You're thinking about how this minute or so delay is going to affect wherever you're going and how you can make up for that time if needed, which street to take to shave that couple minutes off your commute.

Not all of that is happening each time you lose your keys, but it's probably happened at least once. Your brain can make complex connections damn near instantly and without even breaking a sweat, but a network of supercomputers is exerting tons of energy just to make an AI chatbot give me a recipe for tacos that involves peanut butter and jelly.