Things I care about & don't have control over.
A painful category.
This category is comprised of two sub-categories: good items and bad items. This philosophy addresses the bad only, how to deal with winning a lottery is not addressed.
All items that occurred in the past are either category 3 or 4.
Category 3 items which occur in the future are allowed time/energy only in the form of preparation. Worrying about these items is prohibited.
When life is difficult/painful deal with it correctly and move on, simply because there is no better option.
Dwelling on items you have no control over is prohibited; you MUST let go.
When I was facing the death of a parent from disease, I was dealing with a category 3 item. Thankfully I had some time to prepare for the inevitable. We had a good relationship (1) and we spent quality time together (1) long before the disease appeared. My emotions ran their course, and the entire time I reminded myself "I have no control over the situation, I must accept it then move on, I can not dwell on this." I probably repeated that sentence in my mind over 300 times. Because my health and happiness (1) are important, I made the time to read and talk to others about how to handle the situation (1). I identified feelings of regret (3) as they appeared, and was grateful to know they're expected which made letting go of them (1) slightly easier. This may read as something logical, but of course it was an emotional roller-coaster, however I'm sure it would have been worse had I not made these efforts.