Half Full or Half Empty?

I love, love, love teaching seminary.  I just never know what I am going to get from day to day.  Last Friday we had a lesson where the kids looked at a glass of water and I asked if it was half full or half empty.  Since I have one home study student and the rest are early morning, I got to do this twice.  So interesting to hear their responses.  The early morning kids decided it was half full, but one student pointed out that it was half full unless she was drinking that water. Then it was half empty.  When I asked during the second class the answer was it depends.  Am I putting water in or taking water out?  So, is the glass half full or half empty?