Aren't there a lot of patterns on how we interact with an interface? For example, most people on facebook move their pointers to check their notifications/new

Aren't there a lot of patterns on how we interact with an interface? For example, most people on facebook move their pointers to check their notifications/new messages/friend requests. Wouldn't that produce a lot of "not so random" random numbers? (I am not looking to start a conversation on how random random numbers are, just curious on why they used this specific technique)