"There must be other leaps in life - as momentous as the "mirror stage" - that Lacan didn't mention. Some are universal; others, culturally particular. To understand that your parents are human (and not an element of the natural world), that they're separate from you, that they were children once, that they were born and came into the world, is another leap. It's as if you hadn't seen who they were earlier - just as, before you were ten months old, you didn't know it was you in the mirror. This happens when you're sixteen or seventeen. Not long after - maybe a year - you find out your parents will die. It's not as if you haven't encountered death already. But, before now, your precocious mind can't accommodate your parents' death except as an academic nicety - to be dismissed gently as too literary and sentimental. After that day, your parents' dying suddenly becomes simple. It grows clear that you're alone and always have been, though certain convergences start to look miraculous - for instance, between your father, mother, and yourself. Though your parents don't die immediately - what you've had is a realisation, not a premonition - you'll carry around this knowledge for their remaining decades or years. You won't think, looking at them, "You're going to die". It'll be an unspoken fact of existence. Nothing about them will surprise you anymore."