What most people seem to forget is that we have more influence over our immediate surroundings than we at first may want to admit.
We definitely have control over our own thoughts which means that we are masters of our own moods. Own moods result directly from thoughts, the way that other thoughts interact with each other. At least logically that makes sense.
I guess that what I am trying to say is that we create the world around us. The environment is nothing more than an infinite collection of energy and movements. It is influenced by the objects moving around within it and the way those objects interact with each other. These are contained and constrained by the laws of nature, many of which can be described using simple mathematical formulae, others to a lesser degree.
People are also objects, complicated and unpredictable I agree. We might not be able to control completely the actions and interactions of others, but we can influence them in a positive way. Even minor actions on our part can result in a chain reaction of complicated events, feeding back on us and improving us for the better.
Think positively about yourself. Have confidence in your actions, and expect the best of all possible worlds, even if disaster may strike you down once in awhile. Find a path through the world of interacting objects which does justice to your beliefs, desires and ever-changing moods.
Next year is full of new opportunities. My challenge at least will be to make the best of things and remain positive at all times.
An interesting book:
Mind Over Mood: Change How You Feel By Changing the Way You Think