Time

There is enough of it, when you have anything to do. 
There is hardly any of it, when you have something to do.
There it ceases to exist, when you have a thing to do.

Relativity, as we all know, has always been theoretical and seemingly distant from experiential reality, at least to me. However, now I have a tangible sense of it in the context of our actions in life. When you have no goal, no vision, or nothing to pursue, time seems to stretch into eternity. It’s a stage where you feel like you can do anything. The next phase occurs when you realize a few things that you want to pursue, and suddenly the perceived abundance of time diminishes. As you make progress and discover that one thing you love and are fully engaged in, you’ll find that time seems to fade away. That, my friend, is the state of flow. But, don’t fret—this is merely the relative time that you perceive; the actual passage of time remains constant. Time, after all, is a constant force.

Three stages of relative time and your state of mind. 
Stage 1 - Depressed.
Stage 2 - Exited and anxious. 
Stage 3 - Flow.

Rest, you know the story. I hope you find your flow. I am figuring one for myself.