I sometimes, actually very frequently find myself over-thinking to the point where I have to stop everything and close my eyes. As an example, just recently I was studying about data science and my brain goes like - What is data? How do you define data? What is science? When did the word "science" change its meaning from natural science to the more broader meaning it has now. How does brain develop new concepts like data science? How does my brain know what is data science and what is not? How does my brain classify information? And it goes on ... All sorts of questions mainly related to psychology come to my mind. After one point, so much is going in my head that I just take a break and close my eyes. All the questions are interesting but lately they have been too frequent and frankly a bit irritating.