"Perception is not from my original world-cluster, it can be very useless and random. Some things I have seen detected includes: lies, probability of death, the most competent person to perform a task, emotions, but also the last time you ate, how many times a person blinked since they woke up, the direction of the nearest person speaking the vowel 'o', random. It will take a few days until you start noticing what it does, and the overloading-preventing spell allows you to shut it off completely."