There are too many kinds of truths to make such a generalization.

What is the reality of the truth?   Do you mean "the truth of the truth"?

Perhaps, as you say, you know the truth because someone has told you.  But perhaps you don't believe it.  Some time later you are shown absolute proof and become convinced.  Did you really know the truth all along, but not know the reality of the truth?  Can you become convinced that the truth is real, and still not understand why it is true?  It seems like there's a lot to be worked out here.

Is truth absolute?  Maybe sometimes.

Even with a simple "yes or no" question, it may be elusive.  What are you willing to accept as absolute proof?

Is there such a thing as spontaneous generation (of life?)  You leave a piece of meat on the kitchen table for a couple of days and then place it in a sealed glass container, confirming that no life forms are present.  You come back in a week and there are flies buzzing around inside the container.  You're convinced that spontaneous generation exists.  Do you understand the reality of the truth?  Do you know the truth? (People once believed this!)

Do butterflies come from moths?  You watch a moth spin a cocoon, then place it in a secure enclosure.  A week later you see the buterfly break out of the cocoon with your own eyes.

Is it true that the cube root of 27 is 3?  Do you understand the reality of the truth?