All negativity is caused by an accumulation of psychological time and denial of the present.
You may find it hard to recognize that time is the cause of your suffering or your problems. You believe that they are caused by specific situations in your life, and seen from a conventional viewpoint, this is true. But until you have dealt with the basic problem-making dysfunction of the mind -- its attachment to past and future and denial of the Now -- problems are actually interchangeable. If all your problems or perceived causes of suffering or unhappiness were miraculously removed for you today, but you had not become more present, more conscious, you'd soon find yourself with a similar set of problems or causes of suffering, like a shadow that follows you wherever you go. Ultimately, there's only one problem: the time-bound mind itself. [...]
What you refer to as your "life" should more accurately be called your "life situation." It is psychological time: past and future. Certain things in the past didn't go the way you wanted them to go. You are still resisting what happened in the past and now you're resisting what IS. [...]
Forget about your life situation for a while and pay attention to your life.
Find the "narrow gate that leads to life." It is called the Now. Narrow your life down to this moment. Your life situation may be full of problems -- most life situations are -- but find out if you have any problem at this moment. Not tomorrow or in ten minutes, but now. Do you have a problem now?
--Eckhart Tolle, in "Power of Now"