Cynicism

At this point there is a few things we call "dark." From what I've heard it's just a tag meaning "we don't know what this is." You've mentioned dark matter which is supposed to account for all the missing mass in the known universe. There is also dark energy, a unknown/detected force that is pushing the universe apart. Lastly, to my knowledge anyways, there is dark flow. Another unknown force which is 'pulling' on large clusters of galaxies in our universe. Personally I'd love to hear the theories on them, I have none to throw up myself sadly.

I'm not a social person at heart so in general I keep my conversations to the point. When it comes to dealing with people I'm fond of I have no issues creating or keeping a conversation flowing. Shared interests are the foundation of most my day-to-day conversations.