Cervante's novel includes a passing reference to a popular refrain: "No todo el monte es orégano." The mountain isn't all oregano. It means that any undertaking won't be all easy and agreeable; oregano is a soft, fragrant herb. Life isn't always a bed of roses, as we say in English.
That's why I'm Mount Orégano in LiveJournal. This mountain is oregano. Mostly.
What's behind your username?
— Sue Burke