Unnecessary/bad things are very easily accessible and attractive in today's life. We get addicted to it very easily which becomes the cause of our sorrows in the long run. In the beginning it is easy to say no to it but once you get used to it, it becomes very difficult to say no.
Can you say "no" to yourself?
I can't say no to my mind from doing unnecessary overthinking. Even I tried but my brain doesn't listen to me.