Answer:
What can you lose that will cause other people to lose theirs too?
Proof you've done your time in school
What is in seasons, seconds, centuries, and minutes, but not in decades, years, or days?
War fought with pieces on a board.
There is one in every corner and two in every room.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.