By Jennifer Maas
May 27, 2015 at 12:00 PM EDT

Natalie Portman once joked in an SNL Digital Short that she spent her time at Harvard smoking weed and cheating on tests. But the real Portman was a bit more thoughtful during her time at the university, something she discussed during the keynote address at Harvard Class Day on Wednesday.

Portman talked about how when she first came to Harvard after Star Wars: Episode I was released in 1999 she thought she “got in only because I was famous” (it was a sentiment she felt others on campus shared too). Portman had “dark moments,” saying on some occasions she was “overwhelmed with what I was supposed to pull off when I could barely could get out of bed in the morning.”

But the actress said the time at school paid off, and taught her some valuable lessons — specifically ones that prepared her for the intense, demanding role in Black Swan which won Portman an Oscar.

“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,” Portman said.