what does the phrase ” sometimes you will never know the value of a moment until it becomes a memory” mean

Drag the tiles to the correct boxes to complete the pairs. match these vocabulary words taken from great astronomers with their definitions. to come between two things, to interrupt the capacity to reason, judge, and act intelligently to form an opinion without strong evidence relating to the sky conjecture arrowright interpose arrowright celestial arrowright sagacity arrowright