Most people can concentrate on only one thing at a time. True, they will often switch back and forth between several things in a short span of time, but at any one instant they will be concentrating on only one thing.
However, when a person becomes emotional, whether angry or happy, they tend to concentrate on the object of their emotion and will not switch to other topics. The greater their emotion, the stronger they will stick with the one idea.
So, when someone comes to you with a problem to which they have
an emotional attachment, no matter what you say to them they will
hear only those parts that relate directly to their problem.
Just like what dogs hear from their masters
(Blah blah blah, walk, blah blah blah,
leash, blah blah blah.
),
everything else will just flow past them,
they will not remember anything else you say.
In such situations, it is important to filter out the emotion and determine exactly what is obsessing the other person. Dealing with side-issues will only waste time for both of you and might make the situation worse.
If the issue is something you can deal with, deal with it directly. Do not make excuses. Do not give explanations.
If the issue is something you cannot deal with, tell the person directly that you are not able to help and then suggest someone that will be able to help. Do not make excuses. Do not give explanations.
Note that dealing with it directly doesn't necessarily mean solving the problem right away. Saying that you'll look into it first thing tomorrow morning will often be a satisfactory response. The need to know that someone will help with the problem can be far greater than the need to have the problem solved.