It turns out it only takes a couple hours to knit a scarf with fatso, 15 mm needles. At least that's what the instructions say. It probably took me five hours. But hey, it's my first project!
Poor Renee happened to come over the day I finished it, so she got stuck with my first scarf. It has a ton of mistakes. I kept accidentally adding stitches, and then I ran out of yarn at the end so I just had to tie a knot rather than thread the yarn through the work.
Then I made one for my mom's birthday. It went much smoother this time, but still took way longer than two hours.