For me it depends on my mood I guess,
Sometimes there are small situations, that doesn’t affect me long term at all and I tend to be a pessimist and get myself depressed thinking about it.
Sometimes there may be relatively impactful things happen and I could be a pessimist or even a realist and understand the situation.
This happened to me in both good and bad situations. (For example my favorite sports team losing a match - in real life that has no meaningful impact in my future, but still I get upset/ depressed over it. and in another time for the same thing I just forget about it easily thinking that’s the nature of sports or there’s always the next match or they just lost one match they still could win the series
So in these situations the difference is my “present mood” so I believe being an Optimist / a pessimist or a Realist changes according to your mood at that particular time.