(Image credit: Win McNamee / Getty Images) I recently tried Bryan Johnson 's tips for anti-aging. And while drinking lemon water and going for a walk before work have significantly helped to start each day feeling physically better, the color-coded Google Calendar staring back at me is inevitably causing some gray hairs. But after reading about Elon Musk's favorite mental model of First Principles Thinking, I decided to give it a try. Musk famously used these principles to realize that the raw materials of a rocket only cost 2% of the finished product, leading him to build SpaceX . I wondered: What if I stripped the "raw materials" of my productivity down to the physics? Because I'm not a rocket scientist, I gave the job to ChatGPT . I told the AI: "Ignore every productivity 'hack' ever written.…