Fig. to waste one's time trying hard to accomplish something that is completely hopeless. You're wasting your time trying to figure this puzzle out. You're just beating your head against the wall. You're banging your head against a brick wall trying to get that dog to behave properly.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
If you try to talk about anything to a person that has a closed mind it will be like you are beating your head against a brick wall.
A person should aim to be an "open minded skeptic" in the words of Andrew Weil MD. In other words you DO NOT have to believe everything you read or hear. But if something intrigues you, research it for yourself from a variety of sources, and then come to your own conclusion.
In religion or lack thereof, if you are trying to convince an Atheist that there is a God or a priest that there is no God...you will feel like you are banging your head against a brick wall.
When I have a client for Dog Training that hires me for my wisdom and doesn't want to listen to my advice even though their way of solving a dog training dilemma is just NOT working...
When teaching that what you eat (including finding out and avoiding your food allergies) can make or break your health. to someone who just wants to eat what they want for example a diabetic who eats lots of cake, cookies and bread because they deserve it...and of course it is killing them slowly...or sometimes quickly ( it is especially frustrating if it is a relative that has serious health issues and won't listen...)
When I went to my conventional doctor (my rheumy) and I told her I had found a holistic doctor and was going to alter my diet...and she said "Changing your diet will not solve anything, eat what you want" Again, so glad I didn't listen to her! Taking the foods I was allergic intolerant to made a WORLD of difference in how I felt. I feel so much better.
I am tired of banging my head against a brick wall...if someone doesn't want the advice sometimes you need to just walk away and say a prayer or just wish them the best...if they are meant to know information they WILL find it.