One day I think it's the greatest idea ever that I'm working on. The next day I think it's the worst that I've ever worked on - and I swing between that a lot. Some days I'm very happy with what I'm doing, and the next day I am desperate - it's not working out!
I think that you really don't have a choice, when you see that things are wrong the only choice you really have is to just do what you can to make it better.

