I think people who can keep themselves mildly distracted with whatever, are in a far better position than someone who keeps "dwelling on the inside". It is very easy to say that "you don't need to believe your thoughts" , but is it practical (think inception)? In my experience, no. Needless to say, the thoughts and their impact differ from person to person. And unless we can prove that it is more likely to benefit than harm from these thoughts, I wouldn't recommend it to anyone.