Momentum

I often think about how many principles from other sciences also apply to psychology and sociology--evolution, uncertainty, entropy, activation energy, etc. One of the most frequent themes I come back to is momentum. It's where the saying, "When it rains it pours" comes from. Doesn't it seem like when you're in a rut, your thoughts and actions tend to keep you in that rut? When you're feeling great, don't your thoughts and actions, conversely, tend to keep you moving in a positive direction?
For example, I've noticed that when I'm tired and/or depressed, I tend to act in ways that keep me moving in that downward spiral. I don't talk to other people as often. I spend a lot more time mulling over depressing things and wishing things were different. I'm not as active in terms of both exercise and hobbies. I do all of these things despite the fact that I know full well that the only way out of my funk is to do all of those things. It's just so hard to do the things that I know will make me feel better.
On the other hand, when I'm already feeling great I do things that keep me feeling great. I enjoy talking to almost everyone I encounter. When I'm by myself, I'm enjoying the moment, thinking about how great things are going, and dreaming about all of the cool things I'm going to do. I exercise a lot more and engage in my hobbies with enthusiasm. Things that would normally stress me out I take in stride.
May life find you all experiencing positive momentum.
p = mv