Freedom is never more than one generation away from extinction. What does this saying mean?

These words spoken by Ronald Reagan, who was president of the United States between 1981 and 1989, represent the idea of defending freedom through the passage of time.

It is not something that is eternal and can be inherited. There is always the danger that freedom will end.

If the teaching of struggles for their freedom is not constantly passed on to future generations, it can be extinguished at any time, and we could find ourselves within a few years remembering times where we were free, believing it would last forever.