Regarding thoughts such as worry, and stress, William James, an American philosopher, and psychologist, said:
"The greatest weapon against stress is our ability to choose one thought over another."
When we view our mind as a tool that should work for us, not against us, we can decide what to think which can contribute to well being.
Learning this skill (which took a lot of practice) has helped me cope with very trying circumstances, disappointments and hardships. That's not to say I don't get stuck in my head from time to time, but I do it far less than I used to. They're useless thoughts -- energy vampires.
What about you --- do you think you ruminate too much? If you used to but don't anymore, how did you change your pattern of thinking?