I find that I can think through problems and emotions more rationally when I run. Somehow the energy that would've been spent on emotions is used up by my running, so I'm able to think things through. Find solutions or atleast come to terms with things happening in my life. I can almost take a step back and see things from a perspective I may not have seen before. Its rather refreshing.
Some days that means running my hardest, others it means just shuffling along deep in thought. Of course those runs are usually done on the treadmill so I don't accidentally go into traffic or something ;) The miles usually just fly by and its awesome!
I highly recommend some activity that helps you clear your mind. It doesn't necessarily have to be some intense form of exercise. I do enjoy gardening, hiking, swimming, going on leasurly walks. But the best form, for me, is to run and I'm so thankful that I can run and hope I can for many years to come.