When I was a kid my mom told me, "Finish everything on your plate. People are starving. Don't waste food." So that's how I grew up. Eating everything on my plate regardless of how much food was piled on there and whether or not I was full. That habit has been very hard to break, and even as an adult I still hear my mom's voice when I see food still on the plate.
Some people use this concept in other areas of life. There is a culture of people who say "never quit" and "finish what you started." I used to be one of those people. Once I started something, I felt I had to finish it. Even if it was a chore. Even if it stopped being fun or edifying. Something inside me drove me to finish. So I won't be a "quitter." And then I decided to change my mindset.
That doesn't mean I do not honor commitments. When I make a commitment to someone, I do everything I can to honor that commitment.
But when it comes to other tasks or projects, I no longer feel the obligation to finish what I started for the sake of finishing it. If I'm not getting something out of it, it's time to move on. Does that mean I quit certain things and therefore am a quitter? Sure call it what you want, but my time is valuable and I'm not going to waste it.
If a book is boring or not providing me with the information I was expecting, I stop reading it and move on. I'm not going to trudge through it just to say I finished the book.
If a tv show is no longer entertaining, I stop watching it (looking at you Walking Dead). Or better yet I read or listen to a podcast instead of watching anything.
And if I am full, I stop eating (sorry, Mom). This means when I prepare meals, I control the portion size. When I eat out, I always ask for a take-home box.
Certain tasks and projects are worth finishing. It is best to figure those out before starting them if possible. For everything else, I refuse to finish based on some feeling of obligation.
Since I changed my mindset, I have undoubtedly left many unfinished tasks in my wake. I suppose this would bother someone who focuses on the past. But I focus on the present and the future. Each day I want to get better at starting tasks that are worth finishing. I encourage you to do the same.