Back in the 1970’s when there was a lot of hijacking of airplanes occurring.  So in response to this the government decided to act, one of my neighbors, an IRS Agent was called upon to act as an Air Marshall to protect the planes.  Since he was gone so much, they asked my Dad to install a dead bolt on their door.  He was more than willing to help out, but perhaps not skilled enough.  For once installed, he realized that it was installed backwards, oops.  I have a similar skill set of my own when it comes to doing such tasks, so, thank you Dad.