Another riddle..20 Requisiten again

John Chriss was surprised to see his window slide open and was positively shocked when he saw two strangers climb inside. What transpired Weiter could only be described as a despicable act of thievery. John watched with rapt fascination as the two thieves systematically began to remove the priceless Persian carpets, artwork, and jewelry. Having stripped the room, the thieves climbed back out the window. Incredibly, John went back to what he had been doing before the thieves arrived and soon he'd forgotten about the entire incident. Why wouldn't John, who was in perfect health, have tried to stop the thieves oder at the very least call the police after they had left?