He's talking about the Lean Startup Methodology, not just being lean in general. Either way, don't think for a second that it's a good idea to avoid reading books and learning from other people's experiences via podcasts and blogs. That, in my humble opinion, would be a huge mistake.

By taking the time to learn about the lean startup methodology, you save yourself the hassle of having to learn these things the hard way. And by "the hard way," I mean "through your own company."

Yes, you do indeed have to read and/or listen to some podcasts, but you'll benefit in many ways that far outweigh the time you spend reading.

One of the core principles of the lean startup is to learn from customers so that you can build a product that people actually want and are willing to pay for. It gives you ideas on how to do this. It also tells you to stay lean and be ready to pivot; to not be hard-nosed to press forward on your original path, because that may not be the best thing for the business. Does this sound like advice that you should be ignoring?

The lean startup methodology isn't the only way to success, but it does seem to be helping people. And to "cut the fat" of learning of any sort (if you want to call it "fat") isn't a good thing. You should always try to learn from other people's experiences because it can save you lots of time and frustration.