There is an old comic strip with two aliens looking down on earth and seeing a man walking a dog, picking up the dog’s poop as he follows behind. The caption on the comic depicts the question one alien is asking the other: “Which one is master?”
Clearly the man is in the service of the dog and not the other way around.
I think about that comic when I consider the way our thoughts stream through our head. Many of the thoughts we have relate to either worrying about the future or regret of the past.
The thoughts are like a river that we jump in and get swept along.
Clearly we are at the mercy of wherever our thoughts take us. Which is quite unfortunate.