I catastrophise a lot; I make situations appear much worse than they are because my mind is a bit of a pessimistic runaway train. I complain an awful lot, but does that just make me a bitch rather than a pessimist? However, I try, whenever I can, to look at the alleged 'bright side' and to think about where I want to go instead of where I cannot go. If laughter is anything to go by, then I'm the most optimistic person alive; there hasn't been a week where a headache hasn't been brought on by laughing (if one has to be ill, may as we'll make happiness the reason).
In the old age 'glass half full or empty' scenario, I can see both ways (optical illusions and such don't usually work on me). I can see how the glass is half empty, but also half full. I think that I'd be more inclined to say that the glass is half full with liquid and half full with gass, therefore it is totally full.
Does that make me a realisticist(?) or just freaking optimistic (it is all full...) ?