Obsessive thoughts

I

I’ve noticed that my thoughts get obsessive over certain things. These thoughts have a peculiar character. Because it is as if I come under a spell. They seem undeniably true and I find numerous signs that confirm them. While I’m under their spell, my mind keeps coming back to them over and over again, I become absent-minded and they fill me with a strange, anxious, restless energy. 

Yet, what often happens is that something happens that breaks their spell and suddenly they seem no more real than any other thought. 

I wonder what other such things go on in my mind that I haven’t really put my finger on.