Lots of people balk at the idea of writing a 100, 200, 300 page novel. So why do we do it? Why do writers... write?
To avoid doing the laundry. "Writing a novel" is a legitimate excuse to get out of almost anything. Don't want to pick up your room or do the dishes after dinner? Just another thirty pages to go!
To avoid talking to people. Why talk to friends when you can have imaginary conversations with your characters instead?
To avoid doing your homework. Along with playing videogames, vacuuming, and taking your car in for an oil change, writing a novel can be added to the lost list of things to do before your homework.
To compliment your glass of wine. Sometimes a glass of wine needs a bit of novel on the side.
To exercise. Nothing like running laps in a novel.
To pretend to be rich. I love writing novels about Porches, castles, and long vacations on the beach... and maybe a murder or two.
To look cool. No, you're not a custodian, a secretary, a parking meter maid or a bank teller. You're a writer. That makes you instantly mysterious, because no one really knows what writers do.
To look not-cool. Writers are also huge nerds, and sometimes that can be helpful, like when hitting on hot nerd chicks.
And finally, the #1 reason why writers write....
Because we have nothing better to do.