Did you just write 50,000 words in 30 days (and not just the same four-letter word 50,000 times)? Is this the first time you've ever written so much? Be honest - did you think you could do it? If the answer is yes, you've just completed a daunting task with something to show for it. This is what a CMOA feels like.
The list of published authors who started their novels from NaNoWriMo is a nice way to shut up the people who say that this is just a writing stunt or a hobby.