Overview
You clean your kitchen when it gets messy, you clean your car when the back seat gets cluttered -- and you should clean your mind when it gets filled up with a bunch of negative things. This isn't a question of ignoring the real problems you may be mulling over, it's a question of letting go of worry. There are things you just can't do anything about -- those are the things you have to stop thinking about today. Move on with good thoughts, and leave the old, icky ones behind.