Following is not my thought but still worth sharing. I cannot quote reference because I don’t remember now.
If an optimist is one who sees glass half full and feels good about it, isn’t he a pessimist actually because he expected glass to be empty to begin with and is happy with whatever he got? If person who sees glass half empty and feels sad about it, then he is actually an optimist because he expected glass to be full to begin with. Whether we are optimist or pessimist depends on what we expect from the future, right?
Changes the whole perspective, doesn’t it? That’s life. What can be taken at face value? Age old wisdom stands overturned.