Why Does It Take So Long To Translate A Book?

Over on his blog, Pat Rothfuss is answering a question from a fan about translations of his books:
Names are important things. And real names, names that actually exist in the world, don’t make a lot of literal sense. This is because real names tend to accrete and evolve over time.
I work hard to create real-seeming names for things in my world. Names that give a strong impression without actually saying anything. Names like Mincet lane, and Cricklet, and Downings.
These real-seeming (but in reality made-up) names sound really good in English, but they’re a huge pain to translate.
2. I have an odd turn of phrase.
If you haven’t noticed, I tend to make a lot of anormal word usements.
Take, for example, the very first page of the book when I say, “It was the patient, cut-flower sound of a man who is waiting to die.”
How do you translate that?
I wish I could speak another language.  I speak fluent shite but that only lets me blend in when I'm kicking around Glasgow.