I'm convinced it's worse than that. I think he originally drew this thing when he was six years old and is so impressed with himself that he thought it was pure genius then and now.
It was also at that time that he became obsessed with the letter X because he loved pirates and treasure maps.
This is what happens when you think you're smarter than decades of lessons in vehicle safety design. Elon Musk is truly a dumb person's idea of a smart person.