The 54-year-old actress old British actress opened up to Time magazine about dating Laurie, the star of the medical drama series "House," when they were both undergraduates at Cambridge University.
"He was rowing in the Oxford and Cambridge boat race. He was enormous and eating steak all the time. And asleep for the rest of the time," she said. "He was also very funny."
The two have remained friends. Laurie, 54, was on hand to celebrate his ex-girlfriend receiving a star on the Hollywood Walk of Fame in 2010.
"Everything she did just oozed talent," Laurie recalled during the ceremony. "She said talented things, she wore talented clothes, she rode a talented bicycle, she made talented spaghetti. She is a truly remarkable person, a very good friend, and I could not be prouder."
In her latest film, "Saving Mr. Banks," Thompson, who famously brought Nanny McPhee to the big screen, returns to familiar territory as P.L. Travers, the author of "Mary Poppins."
"The nanny story is essentially the Western," Thompson told Time. "It's the stranger from out of town who comes into the situation of conflict, solves the issues using unorthodox methods and then must depart. Shane and Buffalo Bill turn up as Nanny McPhee and Mary Poppins in the female world."
Thompson's husband, actor Greg Wise, recently teased her about her nanny obsession.
"He did say to me, 'Isn't it interesting that P.L. Travers wrote a magical nanny, and you've written a magical nanny. Do you think that behind every magical nanny there's a cantankerous, opinionated old bat?'" Thompson said.