Responsibility
A favorite pastime in the United States is to assign responsibility, and more generally, to find someone to blame. Our thinking seems to be that if something's happened someone must have caused it to happen. In most situations, however, the thing that's happened is the result of multiple causes and multiple people are involved. That is, many things have combined to create the conditions necessary to create the problem.
Among the causes of most problems – our suffering in particular – are our own expectations, actions, and reactions. To relieve your personal suffering, it is important that you accept responsibility for the things that you yourself can change. It is possible to change your expectations, for instance, and so change one of the causes of your suffering. That alone may be sufficient to prevent the problem from arising.
We often think that accepting responsibility is harder than rejecting it. After all, accepting responsibility generally involves some amount of work and perhaps discomfort. However, not accepting responsibility is often harder on you than actually accepting it. You may wind up spending more time and energy trying to deal with the consequences of assigning responsibility to someone else than you would have spent if you had done what you could.
It's sometimes helpful to remember the serenity prayer, which goes something like: May God grant me the courage to change the things I can, the serenity to accept the things that I cannot, and the wisdom to know the difference between the two. (I've found several variations of this, so this is from memory.) If you try to live in this way, you will change what you can without trying to do more than is possible. A nice balance.