From now, back to 1000 A.D. I have over 1000000 (over one million) grand^N parents, where N goes from 1 to about 50.
Over one million people lived over the last 1000 years and I am a direct descendant of every one of them.
The majority lived between 1000 and 1400 A.D., only a handful between 1800 and now.
On average, for every day from then to now, at least 3 people are my direct ancestors. Their bones which still remain are scattered across, but represent a huge pile, tens of meters high.
There are cemeteries out there, that have had thousands of my ancestors buried in them, for centuries already.
Had one of those one million ancestors died as a child (as the majority of their siblings did), my genotype would of course not be here.
The same story goes for you, but you already knew that, or could have known it. It’s elementary.
Everything above is based on some rough calculations. To know more, we should run some computer simulations, Tippler-Bostrom-Kurzwelian style would be best.