The attorney hired by Gov. Chris Christie to do an internal investigation of Bridgegate issued a 360-page report Thursday that finds the lane closure scheme that caused traffic gridlock in Fort Lee was developed and orchestrated by a former Port Authority official, and the governor had nothing to do with it.

During a news conference in his New York office, former federal prosecutor Randy Mastro said after conducting 70 interviews and reviewing more than 250,000 documents "we found that Governor Christie had no knowledge beforehand of this George Washington Bridge realignment idea, and that he played no role whatsoever in that decision or the implementation of it."

Mastro also said: "David Wildstein is the person who originated this idea and orchestrated it. David Wildstein went to Bridget Kelly for approval in the governor's office, and they had an ulterior motive for implementing that decision to in some way target Mayor (Mark) Sokolich in Fort Lee."

However, Mastro said it remains unclear what that motivation was.

"We can say the evidence does not establish that that ulterior motive was to target Mayor Sokolich because he did not endorse Governor Christie for re-election," Mastro said. "The evidence shows that both the governor's office and the Christie campaign knew as early as March of 2013 that Mayor Sokolich would not be endorsing the Governor for re-election."

Thursday night on ABC World News, Christie told host Diane Sawyer while the report backs up what he's been contending all along, "it certainly makes me feel taken advantage of, and also more importantly, I feet like I let people down by not knowing."

When asked if he thought those who were behind the Bridgegate scandal thought it would please him, Christie said "anybody who really knows me would not believe that doing something inexplicably stupid would please me."

The governor also said the report was not a whitewash, because it was prepared by six former federal prosecutors, and he has no recollection about talking to David Wildstein about traffic.

Christie added he's thought a lot about whether he did anything to create a climate where this could happen.

"I don't believe that I did, but I'm certainly disappointed in myself that I wasn't able to pick up these traits in these people," Christie said on the show. "I'm disappointed in myself that I didn't look closer, that I trusted too much."

The governor then said what's happened in the past 10 weeks "ultimately will make me a better leader, whether it's governor or in some other capacity."

He also acknowledged this has been the toughest time in his professional life, noting "you don't sleep, you don't eat, you know, you struggle."

See the video of Christie's appearance on ABC World News below: