As I finish up the documentation (please just shoot me, shoot me now) for my last project I'm transiting to a new project at work. After attending the initial meeting and reading the project document which outlines the goals and some of the details I am totally unsure of this. First there will be a lot of politics involved in just figuring out the actual details and I just don't have the stomach for politics at work. Then the actual programming part is going to be fairly technical and to do it well will require researching algorithms that I barely recall. Then to make it efficient and easy to use.
I can honestly say this is the first time I've doubted if I have the skills to do it. Before I've either known I couldn't do it or that I could (even if it meant figuring it out as I went).