Running around the fields in freedom is what comes to my mind. As for the rings, i've no idea what do they symbolize, but i have a personal symbol, and it has a circle around it. My way of interpretating it it's the never-ending circuit of life, that we must pass over and over again. It can be with goals, and by completing the circle, it starts again, with a bigger goal as the new challenge. Could also as well represent the full cycle of life, and when it's done, we depart this existencial plane, and leave just a case behind, where our souls may flourish and be reubicated in a new corpse, to begin life's cycle once again.

Man. I am way too expressive about this. They're just rings XD

Damn. Forgot to add the main commentary, here. It's an excellent drawing, as as you already saw, i like it a lot :P Good work! ^^