[header] How to deal with a know it all [title] Try to be understanding. [step] Most know-it-alls have a reason for acting this way. Whether it is a personality disorder, the need for excessive admiration, or arrogance, know-it-alls have issues that have to be addressed. 
Trying to understand where they are coming from could go a long way in empathizing with their condition. [substeps] Try to tolerate a know-it-alls behavior and avoid the impulsive fight-or-flight response by understanding that differences between people will always exist.