Trying not to think about ‘X’
This is quite meta. But basically, if you think of something bad / gross happening to someone you love, and then think something along the lines of ‘I would never do that’ or ‘urgh I wouldn’t think about that sort of thing’ you then get a flash of the ‘thing’ and therefore by default you’ve thought of it?
My obsession then becomes the fact I have almost accidentally thought about the thing I don’t want to think about, by trying not to! Then I spiral, of course. And then suddenly it’s weeks later and instead of just a fleeting intrusive thought, there’s a full blown obsession, anxiety, depression.