Unfortunately, Nikola Tesla had an incident in his childhood that definitely left a huge mark on his entire life. When he was seven years old, he witnessed the death of his older brother Danilo in a riding accident. Tesla began seeing visions of the air around him “filled with tongues of living flame” in the years following the tragedy. In his adolescent years, he learned to exercise his willpower to control the visions. He managed something lots of people struggle with, and he continued doing so for the rest of his life – he controlled his brain instead of letting the brain control him.