@PUNKEY,
PUNKEY wrote:paint oneself into a corner = put oneself into an unwanted position.
To expand on that a bit, the phrase comes from the idea of someone painting a floor.
I am not sure how this originally came about, because I've never heard of floors being painted in real life, but just imagine if a floor were being painted.
The painter would not want to walk across the wet paint, because he would mar the work by leaving a series of footprints in the paint.
Now look at the painters in these pictures: