I think there should be a word for this:
When you are deep into writing a passage that has you gripped, banging out the words at a rate of knots, then you suddenly see the cup of tea you made, but completely forgot about. Despair follows, as you know it will now be cold, then — a miracle! — elation, as it turns out the thousand (okay, in reality, 973) words you just produced were actually crafted in exactly the same time that it takes for a cup of tea to reach optimum drinking temperature. Still hot, still with all that wonderful goodness of a Nice Cup of Tea.