Some people think life is mostly bad. Others, mostly good. I think, philosophically, life is neutral. It's not good or bad, it just happens and it is what it is. The events of our lives have no ethical, moral, or emotional significance in and of themselves - we give them significance through our beliefs about them. It is our beliefs about situations that make them "good" or "bad" (and this is a good thing, otherwise life would be pointless).
So then by being careful what we think about situations, we can actually see them as being more "good" and less "bad". Let me explain more, borrowing a useful insight about our reactions to the events of life that I found on Lieslnet.com, an interesting site:
Interesting. There are a series of articles on the site discussing this and what makes us optimistic or pessimistic here, here, and here.
Dr Albert Ellis, prominent psychology researcher developed the ABC model to explain our reaction to adversity.
A is the adversity.
B is our belief about the adversity and
C is the consequence of our belief.
Our reaction to adversity is not so much a result of the adversity but a result of our belief about the adversity.
So perhaps our overall philosophy isn't what makes us optimistic or pessimistic, but rather it is the sum of each thought we have in response to each situation. Our habits of thought become "bedded in", and become quite hard to change. The trick, I think, is understanding what our habits of thought are and finding other ways to think about situations.
It's not a magical "3 steps to a happy life". Life doesn't work that way. But I think it's possible to see more good in life so that we can deal better with the bad, and I intend to try.