Answer:
Born of sorrow, grows with age, you need a lot to be a sage. What is it?
What gets bigger the more you take away?
I have wheels and flies yet I am not an aircraft.
I have a foot but no leg. What am I?
You can see it everyday, but cannot touch it at will. What is it?
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.