
Some are very important and some are only useless waste.
There are so many that it's very hard to separate them. It's like an orchestra is playing...
I remember when I was a boy there where times, when I had only one thought. For example on christmas eve or on the last day of school before summer holidays. I feeled a simple, pure happiness on such days. There where no long term problems or decision to be made.
I never experienced this feeling again when I grew up.
There are some meditation techniques to reduce or shutdown the thoughts, I have to try it. Someday I would really like to be able to switch everything off and enjoy the moment only, like a cat lying in the sun....