They might simply mean "your apparent interest in truth is not an interest in matching reality, but in matching your feelings or something like that." They may or may not be right depending on who you are.

I've found it best to avoid the word "truth" whenever possible. The concept of "truth" implies an objective reality exists and that you know about it. Since we may be in a simulation, in the imagination of a god, or just hallucinating, we can never really be sure about "truth" and I find it boring to play semantic games in order to better hedge the word.

I find it much better to just focus on predictions and beliefs with explicit levels of confidence.

If you're talking about whether the sun rises tomorrow, and you say you predict that it will rise with high confidence, and your interlocutor responds, "That's not my truth," then you can just ask them to break that down into a prediction. Are they saying the sun won't rise? If so, okay, you can test that.

If the disagreement is over something that can't practically be tested, you can still interrogate their concrete predictions and see where they disagree with yours.

Religious people love talking about Truth because it is so confusing. I can't nail you down and show where you're wrong if you refuse to be concrete, so if you don't want to be shown to be wrong, just talk about abstract Truth.

Depends on the context, obviously, but my first interpretation would be "My values are not your values". In popular usage "truth" means more than empirically proven facts about the objective reality -- e.g. people routinely call "truth" what they believe not only in the descriptive but also in the normative sense.

I would recommend making clear two separations: between descriptive ("US economic growth has been slow recently") and normative ("We need to accelerate the US economic growth"); and between facts ("The US GDP grew by 2.4% in 2015"), preferences("Fighting inequality is more important than gross economic growth"), and forecasts, often conditional ("We can accelerate the economic growth by cutting taxes").

Can someone help me dissolve this, and give insight into how to proceed with someone who says this?

You don't, they just don't want to talk about it. Some people can sadly not be saved.

Well, if your justifications are truly marvelous but the margin of this post is too narrow to contain them, you are basically asking everyone to trust you that you know what you're talking about. This makes it an argument by reputation (or, in a slightly more pronounced form, an argument by authority).

I am fairly confident that you have justifications you haven't bothered stating. But that's not the question, the question is whether they are good justifications and this is a much more complicated matter.

I don't know about that being a great gift to the relatives. But maybe I'm just unusually intolerant to fake things.

Use science! X-D

1. Perform an experiment
2. Observe the results
3. Adjust the particulars of the experiment to shift the results in the desired direction
4. Goto 1