Natalie Portman reveals her 'dark moments' in college during powerful Harvard commencement speech

Fresh off the success of 1999's "Star Wars: Episode 1," actress Natalie Portman enrolled in Harvard University.

In 2003, she graduated with a degree in psychology.

But Portman's time at school wasn't always easy.

While addressing Harvard's graduating class on Wednesday, she began by revealing, "I have to admit that today, even 12 years after graduation, I'm still insecure about my own worthiness."

"Today I feel much like I did when I came to Harvard Yard as a freshman in 1999," the now 33-year-old explained. "I felt like there had been some mistake, that I wasn't smart enough to be in this company, and that every time I opened my mouth I would have to prove that I wasn't just a dumb actress."

She continued:

When I got to Harvard, just after the release of 'Star Wars: Episode 1,' I feared people would assume I had gotten in just for being famous and not worthy of the intellectual rigor here. And they would not have been far from the truth. When I came here, I had never written a 10-page paper before. I was alarmed and intimidated by the calm eyes of fellow students who thought that the workload here was easy compared to high school. I was completely overwhelmed, and thought that reading 1,000 pages a week was unimaginable or that writing a 50-page thesis was something that I could never do.

Portman explains that she arrived at Harvard with the intention of proving she could be serious.

"I had been acting since I was 11 but I thought that acting was too frivolous and certainly not meaningful. I came from a family of academics and was very concerned with being taken seriously," she told the crowd.

Looking back, "it's easy now to romanticize my time here," Portman admits, "but I had some very difficult times here too."

"Some combination of being 19, dealing with my first heartbreak, taking birth control pills that have since been taken off the market for their depressive side affects, and spending too much time missing daylight during winter months led me to some pretty dark moments particularly during sophomore year," she explained. "There were several occasions I started crying during meetings with professors, overwhelmed with what I was supposed to pull off when I could barely get myself out of bed in the morning."

Portman says that after taking intense courses and being "seriousness for seriousness' sake," she finally allowed herself to realize that her true passion all along was acting. 

"When I got to my graduation, after four years of trying to get excited about something else, I admitted to myself that I couldn't wait to go back and make more films," Portman told the students. "I wanted to tell stories, imagine the lives of others, and help others to do the same. My Harvard degree represents to me the curiousity and invention that we're encouraged here, the friendships I've maintained."

Portman also drove home another point - using naïveté and youth to one's benefit.

"Make use of the fact that you don't doubt yourself too much right now," she urged graduates. "As we get older, we get more realistic and that includes about our own abilities or lack thereof. That realism does us no favors."

"Fear protects us in many ways, but what has served me is diving into my own obliviousness," Portman explained. "Being more confident than I should be... trying things that you never would have tried. Your inexperience is an asset in that it will make you think in original, unconventional ways. Accept your lack of knowledge and use it as your asset."

Portman says this was especially poignant for her when making "Black Swan," for which she later won the Oscar in 2010.

When first approached about the role, she lied and told the director she was "basically a professional" ballerina. She didn't realize until she had already gotten the job that she was "about 15 years from" being an actual professional.

"The point is, if I had known my own limitations, I never would have taken the risk, and the risk led to one of my greatest personal and professional achievements," said Portman.

But above all, says the married mother of a little boy, "The most fulfilling things I've experienced have truly been the human interactions."

"It's a cliché because it's true - helping others ends up helping you more than anyone," she says. "Getting out of your own concerns and caring about someone else's life for a while reminds you that you are not the center of the universe."

Check out Portman's full speech below. It's worth a watch: