There are few feelings better than finishing a project. That moment you are done, for better or worse, and can put everything away. It's done. No judgements until tomorrow. The client, teacher, judge, etc. may kick you in the balls tomorrow, but you have done every thing you can to produce your best work.
This is a great feeling. What makes it the best for me, is knowing I can just sit down in a comfortable chair, and stare at the wall for awhile. No guilt. Time to decompress. All that time spent on the project, thinking about it every waking moment, is over. Aaaahhh! Time to empty what little brain space I have up there. I'm going to have to start filling it up again soon....sigh. I guess the decompression time is over.