If you don't know the truth about something yet, then it comes by sharing your experiences about that something with others, discussing them and then coming to a consensus. Achieving this involves doing things to test its truthiness. But there's no absolute truth.

Nothing is universal. All is cultural, contextual, subjective, complex, changing, fluid, and profoundly nuanced.

By understanding that "truth" is varied and that seeing or hearing truth depends on where you are standing and how you are listening. Also, reading.

Be quiet. Pay attention.

It is relative. Anyone who tells you any different wants your money, time, or commitment.