I am the only thing that grows when you take from me, and my weight is rarely measured in grams. What am I?

Everyone strives to have me in abundance, but few truly appreciate me until I begin to disappear. Solve the riddle → What has roots that no one sees, is taller than houses, but cannot grow? Solve the riddle → What is it you can do every day, but never on purpose? Solve the riddle → You are driving a bus with twenty passengers; at the next stop, half get off and five new ones get on. How old is the bus driver? Solve the riddle → I can weigh heavily without having any weight. What am I? Solve the riddle →