I have learned in this world that ANYTHING is possible. So I would not say with absolute certainty that it is impossible for someone to complete a flight, from takeoff to the pattern to landing, alone and unassisted with no prior experience. I mean, people actually win the lottery too. But, that is highly unlikely.

Then again, your post said nothing about landing, only flying. Kinda like a few guys did back in 2001, all they needed to know how to do was FLY THE JUMBO, NOT LAND IT. So in that light I would say yes, it is a certainty that someone could fly totally alone... until crash time, then they are no longer flying.