"Problem" means that you are dwelling on a situation mentally without there being a true intention or possibility of taking action now and that you are unconsciously making it part of your sense of self. You become so overwhelmed by your life situation that you lose your sense of life, of Being. Or you are carrying in your mind the insane burden of a hundred things that you will or may have to do in the future instead of focusing your attention on the one thing that you can do now.

Eckhart Tolle

from The Power of Now: A Guide to Spiritual Enlightenment