rachelitis

a rare disease that causes the victim to pull out onto the wrong side of the road occasionally and for no understandable reason. Despite being clearly wrongly, a victim of rachelitis is thoroughly convinced they are on the correct side of the road. There is no cure or treatment, and it is life threatening.

“You’re on the wrong side of the road”
“No I’m not!”
“What do you know, you have rachelitis!”