Bullock became more serious about acting later in high school. She won an award for best actress in a talent competition for her performance in "A Streetcar Named Desire." She also starred in Woody Allen's "Don't Drink the Water," and was always putting on performances in school assemblies. Bullock wrote a lot of sketches with Sowers and was eager to perform them whenever an opportunity presented itself.
For a high school talent show one year, Bullock announced she wanted to do something creative in between the skits.
"I would come out to introduce the next act and then she would come on in a character and start tap dancing," said Sowers. "Or she'd come out and start juggling or she'd come out and start singing...and she stole the show."
Stealing the show was an area in which Bullock excelled. She began her screen career in a supporting role in the TV movie "The Bionic Showdown: The Six Million Dollar Man and the Bionic Woman" alongside television veteran Lindsay Wagner -- the original bionic woman.
"My first gut reaction was that she was just darling," said Wagner. "When we started working, she was kind of shy. "And once in a while, she'd relax and then I'd see how funny she was."
Wagner said her young co-star oozed charisma and personality. She said she could tell that one day, Bullock's flame of talent would ignite on a national level.
It took a few forgettable films like "Who Shot Patakango?" before Bullock landed a role in the hit action movie "Speed," with Keanu Reeves. The film catapulted her into the national spotlight as a girl-next-door the world could fall in love with.
"When 'Speed' came out...there she was, oh my gosh, there's that girl. She's great. Look at her and she's just wiping up that screen with her talent," Wagner recalled.
From there Bullock became comedy gold. "She has no fear of a laugh at her expense," Sowers said, "She never has."
Watch "Before They Were Famous," on a special edition of "20/20" Tuesday, March 2 at 10 p.m. ET