Michael J. Fox was on the Late Show with David Letterman last night to talk about Parkinson’s Awareness Month (now through the end of April), from his own diagnosis to the steps his foundation is taking for finding a cure.

“It was pretty scary,” Fox told Letterman about the time after being diagnosed with the chronic and progressive disease. “I was 29 years old, so it was the last thing I expected to hear. I thought I hurt my shoulder because I had a twitch in my pinky … and the doctor said, ‘You have Parkinson’s disease. The good news is you have about 10 years of work left.’”

Perhaps to his doctor’s surprise Fox is still working 22 years later. Eventually, Fox added, he realized he could have been diagnosed with something worse, terminal even, so he learned to accept it. And when he realized he was also in a position to make a difference, he added, “it’s just, like, quit your bitching and get on with it.”

According to The Michael J. Fox Foundation's website, since 2000, the foundation has funded more than $450 million to speed a cure for Parkinson’s disease; 52 percent has been invested into altering the disease, while 22 percent has been invested into defining biomarkers or ways to identify the disease. Fox explained to Letterman identifying biomarkers is a way to spot the disease before it develops,

Additionally, he and the foundation are looking into possibly developing a vaccine — to which Letterman was curious a bit more about the process of meeting these goals. Fox said he encounters disappintment all the time; "science is hard."

"I have great admiration for you," David Letterman said. "You're the original tough guy."