March 27, 2014 -- New Jersey Gov. Chris Christie said today that former aides were "inexplicably stupid" when they allegedly shut down lanes of busy George Washington Bridge and flooded a New Jersey town with traffic.

The exclusive interview with ABC News' Diane Sawyer was his first television interview since his January press conference on the George Washington Bridge lane closure scandal.

"When things were first reported, I said: 'This can't possibly be true. Because who would do something like that?'" Christie told Sawyer. "Sometimes, people do inexplicably stupid things."

"And so that's what makes it so hard then to, as the guy in charge, you…none of it made any sense to me," he added. "And to some extent still does not."

Watch the full interview with New Jersey Governor Chris Christie TONIGHT on "World News with Diane Sawyer" and on "Nightline."

Two of Christie's aides have been fired for allegedly closing several lanes of the bridge, causing a massive traffic jam in the town of Fort Lee, N.J., to punish the Democratic mayor of the town.

The interview, which will air tonight on World News with Diane Sawyer, comes as a law firm retained by the Christie administration released a report exonerating him from any knowledge or involvement in the scandal.

Christie, a Republican, said that the more than two month long controversy took a toll on his professional life.

"You don't sleep, you don't eat... you struggle. You struggle," Christie said. "But I do believe that what doesn't kill you makes you stronger."

"It's been a very, very tough time professionally," he added. "Not the toughest time in my life, but certainly the toughest time in my life professionally."

Christie was asked about allegations that the report was whitewashed to protect him and about allegations that David Wildstein, a former Port Authority official involved in the scandal, told him about the lane closures and about how the scandal has impacted his 2016 prospects.