Mr. Bean is Autistic
He shows all the signs of autism, first and formost, problems with social skills.
Mr. Bean is actually an alien or fallen angel.
Which is why the opening shows him falling out of the sky in a beam of light. His odd behavior is actually a result of him not being human and not really understanding how humans are supposed to behave.
Mr. Bean is a descendent of Sawney Beane.
Better hope that he is not cannibalistic.
Mr. Bean is the Black...Vegetable.
Another Blackadder descendent.
Mr. Bean and Teddy are symbiotic to each other.
Explains how he treats Teddy like a real person so much.