Somewhere in the future, someone exists who shares your DNA but will never know you. Your great-great-grandchild. Your great-great-great-grandchild. Someone who will be born long after you’re dead, who will carry some fragment of you in their cells but will have no memory of you, no stories about you, no connection to you except blood.

This experiment is about writing a letter to that person. Not to your children or your grandchildren—to the descendant you’ll never meet, the one who will be born fifty or a hundred years after you die.

Start with “Dear Unknown Descendant.” Then tell them who you are. Not your accomplishments or your resume—who you actually are. What you’re afraid of. What you love. What you believe. What you’re still trying to figure out.

Tell them what the world is like right now. What year it is. What’s happening politically, culturally, technologically. What people are worried about. What people are hoping for. What it feels like to be alive in this particular moment in history.

Tell them about your ordinary life. What you do for work. What your house looks like. What you eat for breakfast. What you do on weekends. What makes you laugh. What makes you cry. The small things that fill your days.

Tell them about the people you love. Describe your partner, your children, your parents, your friends. Tell stories about them. Make them real. These people are your descendant’s ancestors too—help them know who they came from.

Tell them what you hope for them. Not in a preachy way—in a real way. What do you hope they inherit from you? What do you hope they avoid? What do you hope the world is like when they’re born?

Tell them what you wish you’d known at their age. Tell them what you’ve learned. Tell them what you’re still learning. Tell them what you got wrong. Tell them what you got right.

Be honest. Don’t try to sound wise or impressive. Just tell the truth about who you are and what it’s like to be you, right now, in this moment.

When you’re done, print it out. Put it in an envelope. Write on the outside: “To my descendant, to be opened in the year 2100” or whatever year is far enough in the future that you’ll definitely be gone.

Give it to your children. Tell them to pass it down. Tell them to make sure it reaches that future person, that unknown descendant who will need to know where they came from.

Turns out immortality isn’t about being remembered by everyone—it’s about being known by someone, even someone who will never meet you, even someone who will be born into a world you can’t imagine, and when that future person opens your letter and reads your words and learns who you were and what you believed and how you lived, they won’t just be reading about a stranger, they’ll be meeting their ancestor, they’ll be connecting to the long chain of people who loved and struggled and hoped and failed and tried again, and they’ll understand that they’re part of something bigger than themselves, that they carry forward not just your DNA but your humanity, your specific way of seeing the world, your particular wisdom and foolishness, and that connection across time, that reaching forward to touch someone you’ll never meet, that’s the only kind of immortality that actually matters.