What is the meaning of the phrase “bang your head against the wall”?

The phrase “bang your head against the wall” is an idiom used to describe a futile attempt at achieving something. It implies a situation where someone is attempting to solve a problem or reach a goal, but is making no progress and is likely to fail. The phrase is used to express frustration and exasperation at the lack of progress and the feeling of being stuck in a situation that cannot be resolved. It can also be used to describe a situation where someone is trying to force a solution or outcome, but is met with resistance. In this sense, the phrase implies a sense of futility and hopelessness in the face of a seemingly insurmountable obstacle.