A new report includes details of Biden's irritability when being briefed each morning.Andrew Harnik/Getty ImagesA new report details how Biden had long been in a cocoon before his disastrous debate performance.Top aides reportedly have to be careful about what they tell Biden — for fear of setting him off."It's very difficult, and people are scared shitless of him," said a top aide.In the wake of President Joe Biden's disastrous debate performance, top White House aides are starting to open up — albeit anonymously — about how things got to this point.According to POLITICO, one key explanation is that the president is in a cocoon, surrounded by a tight circle of top aides who keep him isolated in an effort to manage public perceptions of the 81-year-old president.That reportedly includes tightly managing the information that the president receives in his daily briefing in an effort to avoid triggering a negative reaction from him."It's like, 'You can't include that, that will set him off,' or 'Put that in, he likes that,'" a senior administration official told the outlet.