These thoughts are considered benign, as they do not stay long enough, which assumes they are not even important, and therefore, they are not effective in our psyche, health, or well-being...but are they benign? Can they be potentially harmful if habitually dark and brooding? Let's consider this more closely.
Consider a couple of famous people. Consider first someone of the modern world. Consider....Stanley Kubrick. If you read a general bio of Kubrick's movie career, there are telltale signs of his intense thought provoking mind strewn all across his entire career in filmmaking and screenwriting.
Kubrick was an intense person, "bookish" and introverted, to say the least. He was melancholic and inhibited by nature. Luckily his father taught him how to play chess at a very young age, which probably worked well with his intensity, and helped him become even more patient with all his perfectionist propensities, making him one of the most valued, original, and initial special effects film "thinkers" of his time. He seemed to have a propensity also to fearing the "bomb" but then again, most people were afraid of the implications of nuclear power in the 50s. Finally, he seemed not to be affected by other film industry people's ideas. He was dogged in portraying film as he saw it in his own intellect.
One might consider also the suggestion that while one's thoughts are a boon to one's professional pursuits, it can also be a detriment to one's own health, which seems to be the case for Kubrick. His themes were anything from black comedy, to psychological drama, to scathing thriller/horror, to science fiction....he was a master at creating in us mental disturbances. Think of "A Clockwork Orange," "The Shining," and "2001: A Space Odyssey," to name only a few.
Really, one cannot write an entire essay about a subject and win converts to a concept about how thoughts create one's survival or demise. That is left to my book of essays. All I can share here is a thought: "Sticks and stones can break my bones, but words can never hurt me..." How about words in our heads, and can hurtful words in our head ultimately hurt us? Stay tuned for tomorrow's blog day....I'll be back on this topic.