Many of Sun Tzu's ideas are common-sense enough, but succinctly put here. It's a quick, easy read, so it's not hard to make the case that it's worth the time. But gliding through it effortlessly will make it difficult for the ideas to really stick. So I guess it's also easy to make the case for at least one re-read. I'll probably give it another go myself in the near future, but for now I'm happy with the bits and pieces I've gleaned. It certainly didn't change my life or anything, but then I didn't expect it to.