Hmmm. Parts of it are based on research going back more than 60 years. But it wasn't as *necessary* prior to the kind of lifestyle we're all in now. When people had a longer period of time to learn new skills, and less distractions taking away brain cycles, the way we acquire skills didn't have to be all that efficient and effective. Now, we're all pretty overwhelmed most of the time AND the things we need to learn are changing constantly (especially if you work *in* tech). Us, our employees, our users are all dealing with a lifestyle that makes learning new things especially painful no matter how motivated we are. There are just too many factors working against us. So I could say this book *could* have been written many years ago (with different references to technology of course). But it is only recently that I think we all have become more desperate in our need to reduce cognitive resource waste and to acquire skills more quickly and with less stress.