I was just reading this post over at Mike Lee's BizThoughts blog. He talks about the paradox of knowing something so well that you can't be creative or innovative about it anymore. You become so set in your ways that it's hard to remember what it was like before you were the expert. I've certainly experienced this myself, and I've taken to calling this situation, "idea fatigue."
Idea fatigue happens all the time. I experience it at work frequently, where I'm faced with a complicated problem that takes days to solve. I feel like I walk down the same path and slam into the same brick wall over and over again. For some reason, I just can't back up far enough to see an alternate path. Mike's post suggests that the best way to get around idea fatigue is to bring in someone else with a fresh perspective. Someone who hasn't worked on the problem can see all paths instead of just the one you've started down. I've used this technique any time I've worked on a problem for more than a couple days without finding a solution. The funny thing is, I've found another solution as well.
I started noticing a while ago that when I gave up on a problem, I ended up solving it very quickly thereafter. This first started happening several years ago at my second job, when I'd be sent down some rabbit hole to figure out how to make the browser do something crazy. I'd spend days trying everything I could think of before approaching my boss and telling him that I couldn't do it. No sooner would I leave his office then the solution would come to me. This pattern repeated itself several times and frequently enough that I began using it to my advantage.
I'm not sure if it will work for everyone, but for me, giving up on a problem somehow resets my thinking. It could have to do with relieving the expectation of solving the problem, or just wiping the slate clean enough to see another solution...either way, it works. Down with idea fatigue!