I think one of the main things a lot of us have to learn is how to let go of things. If it's resolved, then let it go, don't cling on to it. Just move forward.

Pretend you're a river. A river can't go backwards. Once the rocks and rapids have passed, the river calms and smooths out, continuing forward and not backward. The only thing that stops a river is to build a dam and force it. So, looping negative thoughts are the dam, turning you into a lake, and keeping you stuck. So, don't be a lake, be a river.