Usually, when I hear people say that, it's more or less "agree to disagree" when they hear someone else saying falsehoods and don't have the energy to deal with it. Or, when people have a disagreement or argument, each of them have their own "truth", that is, the story of what happened from their point of view. Personally, I've never heard anyone confuse those phrases for "objective reality is whatever I want it to be".
