(I put this on SO, but it got a couple close votes saying it belonged here instead...)

I've spent the last year as a single person team developing a rich-client application (35,000+ LoC, for what it's worth). It's currently stable and in production. However, I know that my skills were rusty at the beginning of the project, so without a doubt there are major issues to the code. At this point, most of the issues are in architecture, structure, or interactions - the easy problems, even architecture/design problems, have already been weeded out.

Unfortunately, I've spent so much time with this project that I'm having a hard time thinking outside of it - approaching it from a new perspective to see the flaws deeply buried or inherent in the design.

How do I step outside my head and outside my code so I can get a fresh look at this code so I can make it better?

Is this less of an issue than I think it is, or is this a problem for other people as well?