Your grandmother was frightened before you were born.
Not in the ordinary way that people are frightened, the startle at a loud noise or the anxiety before a difficult conversation. I mean something more precise. Decades before your parents met, before you existed as even a possibility, your grandmother experienced something that changed her at the molecular level. Methyl groups attached themselves to specific locations on her DNA. Genes that had been active went quiet. Genes that had been quiet began to speak. And that alteration, that chemical annotation of experience, passed forward.
You carry it now.