Sunday morning, we went to our usual once a month pagan spirituality service. One of the opening activities if you will is to ground ourselves in the present--"Be here now!" Gather up those parts of you that are in tomorrow or back in yesterday or a decade ago and focus on the moment. Thoughts will drift in "what should I make for dinner? how will I ever finish my book? why is the little one fidgeting?" but they just pass on by. It's a good reminder of how our minds are a buzz of activity, yet we can quiet those wayward thoughts, tame them simply by noticing them and then letting them float away.
Mental clutter can bring you to a stand-still. Regret, what if, why, those can run your little neurons ragged if you let them. Rather than circling and circling, let those thoughts that keep you stuck run away, like wild horses on the plains. You'll find that they just keep running, and before you know it, your mind is on other things.