Back to reality - this is how we call this feeling. No more no less. If you get overflown with great positive emotions there still is the great chance that you might loose that all just in a small moment of time when you get back to your desk, others are so worked up about something. They just drain out all the positiveness that lies within you and feed on it. And they ain't satisfied with it so they got more and mores anxious and vicious, just like a wild beast that just tasted a fresh blood.
This feeling is called "back to reality"....