This is a great post. It basically says that when you have a problem that seems intractable, look for the conditions under which it is intractable and see if the conditions apply for your specific case. Many times they don't. And even if they do, you can often pretend they don't and still get solutions that are good enough.
For a small pearl on problem solving, I recommend "How to solve it"[1], by the great mathematician George Pólya[2]. It teaches you simple techniques you can apply when you are stuck, like "draw a picture", "think about a similar problem you already know the solution for", and "solve a relaxed version of your problem". It all looks pretty much like common sense, but it is not. It's one of those few books I think everyone should read (whenever they are stuck).
[1] http://www.amazon.com/How-Solve-Mathematical-Princeton-Scien...