Although don't meditate enough, I keep trying. Yesterday I got an insight: that ruminative non-productive thought is both effortful and, well, non-productive.
The image that popped into mind as I was meditating was of the task of moving heavy bags full of sand from one room to another in a house. So say the kitchen needed a bag, and you had to move it from the bedroom, and then another two bags from the living room to the bathroom, and so forth throughout the day, without much purpose.
So many of my thoughts seem to be of that nature. You can work hard at thinking about your life but if it is just moving sandbags around, it is rather pointless, but also very tiring. Productive thought is simpler, without as much wasted effort, and also more productive in that it simplifies problems rather than complicating them.