"How to preserve data for a thousand or even ten thousand years?"

What will happen to your QQ number after you die? These topics used to be very popular on domestic forums. What will happen to your email? What will happen to the movies you downloaded? In fact, it's quite good for personal data preservation to last for decades. The hard disk life span is about 10 years and the CD life span is about 30-50 years. So how to keep data for a long time?