I would use the word 'drained' rather than tired or worn out. I think being excited takes over and counteracts it. When I finished my QXC, i didn't feel tired until I got home, and even then, it wasn't that bad. I have been more tired, for instance when I done my first dual nav - it was so bad, I was just knackered. Stress has a lot to do with it I think, so the more stressful a flight, the more tired you will be.
That's just me anyway
