Harry Potter: 7 Times Harry Was A Complete Idiot
3. When He Forgot About Fire – The Half-Blood Prince
During the closing stages of The Half-Blood Prince, Harry and Dumbledore venture into a cave which they believe to be the home of one of Voldemort’s many Horcruxes.
Shortly after their arrival, Dumbledore tells Harry there are Inferi (dead bodies enchanted by a Dark Wizard) beneath the surface of the lake. He also explains that like all creatures which dwell in cold and darkness, they fear light and warmth, or – more specifically – fire.
Unfortunately, despite being told this vital piece of information minutes beforehand, Harry forgets Dumbledore’s advice as soon as the Inferi start to attack. He uses a variety of useless spells and ends up being dragged beneath the surface as a result of his stupidity.
Had it not been for Dumbledore’s timely recovery, his lapse in concentration may well have been fatal.