I get tired of hearing this crap from people who are happy with the status quo. I don't care how good things are, there is always room for improvement. I am an optimist, which means I constantly look for opportunities for improvement. Pessimists think that improvement is not possible, so they tell you to be happy with the world as it is.
Their favourite is the old half-full vs half-empty argument. So here are a few different responses for you to use next time someone accuses you of being negative because you think things can improve...
1. My dog just knocked my glass over. Thankfully, it was already half-empty. Why is full better than empty anyway? What's wrong with empty?
I was out with some friends who like to drink. It irritated them that my glass was still half-full when theirs were empty. Fullness was a sign of failure. As soon as their glasses were half-empty, the waitress appeared and asked cheerfully if she could sell them another one. An empty glass is an opportunity to have another drink! Yeah!
2. My taiji teacher used to tell me that martial arts is the unity of two opposites: emptiness and fullness. Emptiness is the ability to absorb an attack, to bend like a reed in the wind when a tree would resist and be blown over. Fullness is force, the ability to push and pull. If you meet force with force, something will break. Use emptiness to neutralise fullness, fullness to overcome your adversary.
The master must be both full and empty, as required, able to adopt whichever quality is most appropriate at any moment. A glass is both half-full and half-empty at the same time, you can put water in, or take water out. It is a symbol of perfection and harmony. Why spoil it?
3. According to a designer I once met, the glass is the wrong size for the quantity of water. The half-full/emptiness of the glass indicates that someone hasn't thought properly about what they are trying to achieve. Design is a statement of intent, and an inapproriately-sized container says that you're not committed to creating the perfect solution to your water-containment needs.
Back in my drinking days, when my glass at Carnegie's used to go mysteriously empty very very quickly, my favourite waitress didn't just sell me another drink. She sold me a bigger drink. A pint of Bacardi and Coke doesn't go half-empty quite so quickly, and when it does happen, you can confidently say that it's still half-full.
4. Have you seen the movie Avatar? Why don't the sky people understand the Na'vi, after years of study? Because "it's hard to fill a container that is already full." The people who are telling you there is no problem are the ones who are not listening. Forget about problems, see what you can learn that you didn't even know was there to be learned.
5. Try and work the phrase "drinking from a glass of very small beer" into your reply. I got it from Terry Pratchett, and loved it because it combines the need for a bigger drink with the lovely suggestion that someone is a loser.