Why do certain people think that they have someone all figured out if it turns out they're gay?

It's much easier to deal with labels than it is to deal with people. Shallow thinkers *do* have labels all figured out, even if the conclusions are unjustified and all wrong. People, though, are much more complex. No one can honestly claim to have any single person all figured out. So labels are used for ease of thinking, and shallow thinkers see only the labels rather than the person themselves.