This happened to a friend of mine way back in the way back days. His car would only go backwards as he thought he couldn't a forward gear so he he drove home in reverse and parked it. He thought his box was stuffed and being an apprentice he had no money so he had to save! anyway 2 weeks later, he released the hand brake mechanism and presto he now had forward gears. His brother inlaw who was the last one to work on the car adjusted the hand brake cable so it actuallly worked but did not tell my mate who always thought his hand brake just did not work! True story from 27 years ago.