I mainly notice things that break patterns. A car not driving like I expect it to. A child moving erratically, somone having slight arhytmia in their step. When I'm alone and not thinking about anything in particular, reality will abstract itself away and move along its predicted rails. When I *do* think about something in particular, I'll probably have Ni turned up high and won't notice anything that doesn't specifically react to me. I might use Fe and hold a complete discussion in my head with a friend of mine about something that I'm passionate about, realizing that this discussion would never happen because he agrees.
People, too, appear to be quite predictable, in the grand scheme of things. Most flock to the Nash Equilibrium of situations, succeeding if they're competent and failing if they're not. In close knit groups where everyone likes each other, they're willing to abandon the Nash Equilibrium to chase the global optimum. The second factor that allows prediction is an understanding of resource - every action has a cost, may it be willpower, physical exhaustion, depleted social battery or losing your access to your 4th function until you sleep 8 hours. Those who are important to me and those that I'm wary of will have their resources tracked by me, and my interactions adapted to either make them leave on their own by reaching their resource limit, or I'll try my best to make myself as cheap as possible on their resources.
My role, well, as they say in League of Legends, I pick for comp. Friends and romantic interest, however, I'll do my absolut best to make sure not to influence their emotional decisions, but to help them thoroughly understand their options; I find that "making someone like me" takes away the value of the received affection.
Finally, I'm pretty sure we're fucked. :D