A lark is not a fleeting feeling. It’s “a quest for amusement.” This is pretty much the only thing that explains all of the behavior. He was doing it for fun and no one stopped him in time. Partly because, as has been reported, so many in his inner circle thought he wasn’t serious about it.
He entered into an entirely reckless contract because he was riding the high of his Big Joke. Not sure what’s hard to believe about an egomaniacal self-described troll getting himself into a tricky situation. Schoolchildren do it all the time.
Who knows what the deal is with his relationship with counsel but go ahead and read some of their filings to see what a clown show it is. Some of them seem to have been written by Musk himself and making claims that don’t even resemble legal arguments.