What happens if someone loses their bitcoin? Let's imagine that I buy 10,000,000 bitcoin for example. Does the system need to re-create those money?
No, bitcoin system will not reproduce it again. There is a total of 21 Million bitcoin supply. If that supply was already bought or created and loss, it will not reproduce again. So be safe about your bitcoin. Even though it will last a hundred of years, we cannot tell when will it vanish.