Anyone else have benign paralogia?

I occasionally have weird thoughts springing into my head. Things like: turtle gravitation, platitudinous pineapples, or other nonsensical phrases like that. They began occurring when I was in high school and then stopped for many years until I reached about 70 years old. When I was in my early 20s I read that it was a benign condition and I never pay much mind to these thoughts - they always come only when I am alone. I have lived a pretty normal life, never anythiing more than occasioal depression for which I never took any medicine, and in fact I have been told that I have a very logical mind and am in the sciences. My brother is schizophrenic although he never speaks nonsense, he just reacts inappropriately at times. I am just wondering if this kind of thinking is common in the relatives of schizophrenics or in the general population.