Everyone has his own thought processes and mostly accustoms well with them. Sometimes this however becomes problematic if it interferes with the functioning of the individual or causes distress to them or the people around them. So to say, if such thought scenarios interfere with your work productivity, relationships or cause you significant disturbance as in simply being a waste of time, seek a consultation as it may be some disorder like generalized anxiety disorder, obsessive compulsive disorder which can be managed with therapy or medication.