Answer:
Ten men's strength, ten men's length. Ten men can't break me, yet a young boy walks off with me. What am I?
I am heavy forward but backward I'm not.
I am easy to waste and unstoppable. What am I?
I'm where yesterday follows today and tomorrow is in the middle. What am I?
I let water fall on you while everyone else stays dry.
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.