Am I mad?

I committed myself to making the jacket in the Noro Volume 26 book yesterday! It's a very 'elaborate' pattern and Amanda (Kangaroo) is going to run a blog to make my progress, and has ordered the yarn for me. The pattern calls for Kureyon/Kureyon sock but, as there doesn't appear to be a sock version of the shade I liked (and Kureyon is a bit scratchy), I've gone for Silk Garden/Silk Garden Sock which will cost more but will, I think, be worth it. I am going to buy the yarn with my birthday money so won't be starting it until around October 1st.