It's just a weird illustration for me, mathematically speaking. You could take it as a "glass half full/empty" card except that it's NOT half full or half empty, not with an uneven number of cups.
Using your tutor example: let's say said tutor is the ONLY tutor in the world in posession of knowledge that you need/want and you didn't quite get that far in your studies before he left. So, you may look back fondly on your time together, sure, but now you will NEVER have the opportunity to get that knowledge. Could be potentially devastating with regard to your future.
If there are other tutors who can provide that knowledge and they are available to you, the loss is disheartening, but not devastating (even number of cups). If you now have no way to progress in your studies, you're in serious trouble (odd number of cups with most of them being spilled).