Consider how much more you often suffer from your anger and grief, than from those very things for which you are angry and grieved. – Marcus Antonius
The quote requires a careful reading.
You must be willing to consider that there are things that you think about that cause you anger and grief and things that actually cause anger and grief.*
* And, for the Advanced Class on this, you must consider that many of the “actual” things that cause you anger and grief only do so because of beliefs you have about things and how things should go in your life.