Deja Vu is a 'short circuit' in the brain. It happens when you process information but your brain accidentally stores this information in the wrong place, leaving you to believe that the event has already occured and is occuring again.

Only one way to stop getting Deja Vu - Don't allow your brain to process and store information. When you're high your short-term memory stops working - so stay high and you won't get Deja Vu anymore.

(P.S. Deja Vu is french for 'Already seen')