The actress was just 18 years old when she was caught on camera lighting up a marijuana pipe with her then-boyfriend Michael Angarano.
The shocking photos hit the tabloids just days after the first Twilight film was released, and Stewart admits the scandal was the wake-up call she needed about life in the spotlight.
She tells Vanity Fair, "You can Google my name and one of the first things that comes up is images of me sitting on my front porch smoking a pipe with my ex-boyfriend and my dog.
"It was (taken) the day the movie (Twilight) came out. I was no one. I was a kid. I had just turned 18. In (the tabloids) the next day it was like I was a delinquent slimy idiot, whereas I'm kind of a weirdo, creative Valley Girl who smokes pot. Big deal. But that changed my daily life instantly. I didn't go out in my underwear anymore."