- He thinks I'm some stupid thing, he does! Well I didn't ask to get beaten! I didn't ask to get beaten up by my dad and take out my rage on everyone else over and over again and turn into some... some fucking monster!
- Flash Thompson
Flash grew up a few blocks from Peter Parker's house in Forest Hills, Queens, New York. He lived with his alcoholic father, Harrison Thompson, his mother, Rosie, and his younger sister, Jesse. He was constantly abused by his father and Flash accused his mother of never supporting his son.
As a child, Flash was constantly ridiculed by his neighbour, Duncan Matthews, who picked on him, but his father took him to confront Matthews and told his son to prove he was a man and willing to fight back; he was instructed to hit Matthews repeatedly as his father ordered him to continue. This, along with his father's constant abuse towards him, eventually led to his own violent, bullying nature.
He was also extremely insecure about his personal life. He was friends with Peter during preschool as a kid. During that time, he earned the nickname "Flash" by Peter because of his tendency to streak all the time, but this incident only further escalated his father's ire against him. Flash turned against Peter after all the abusive beatings he took from his father, and started bullying him.
He eventually became a classmate of Peter Parker, often violently bullying him, and became the quarterback of the football team. He also harassed and abused his girlfriend at the time, Liz Allan, a cheerleader who had trouble reconciling with her family, and Flash didn't realize that his abuse towards her was making her mentally unstable. He became an alcoholic himself because of being abused by his father, and would often come to school tired or exhausted because of the effects of him drinking and also motivating his aggressive behavior. He also threatened everyone that if they ever reported his bullying, he would have them arrested since his father is a police officer, earning him the fear of most of his classmates.
When Peter's uncle died, Flash felt sorry for him and apologized to him for bullying him, which Peter accepts. After the debut of Spider-Man, Flash idolized him and became his number one fan.
Flash was still conflicted by his father and refused to talk to his mother, and his sister was the only one who supported him. He further escalated his abuse on his ex-girlfriend and his friends. He eventually beated up Liz in a fit of rage, which made Liz go to a hospital. He was also expelled from Midtown for all of his actions and wasn't allowed to graduate with the rest of his class. Deep down, he felt that he deserved it for afflicting so much pain in those like Peter, Gwen, Eddie, and Harry.
Flash eventually moved out of his home, wrought with guilt for his actions as a bully and for hurting his family, and moved to an apartment near Queens. He lived a very depressing existance, drinking nothing but beer and eating nothing but junk food.