I Built A Second Brain With Codex in 15 Minutes (Matt Wolfe)

*Free Guide to Build Your Personal AI Wiki:* https://clickhubspot.com/ix2i In this episode, Matt Wolfe (Future Tools) walks Kipp through the exact stack he uses every day: Obsidian for storing what he reads and watches, and OpenAI's Codex for cross-linking it all into a searchable "second brain" that gets smarter every night while he sleeps. They cover the proactive AI morning brief, automated competitive intelligence, journaling workflow, and the marketer-specific use cases (AEO audits, ad testing, product marketing audits) that make this stack a 10x productivity unlock. 📌 WHAT WE COVER: → The Karpathy tweet that started the "LLM wiki" movement (20.8M views) → Obsidian explained for non-developers — what it is and why it's free → The Obsidian Chrome extension that clips YouTube transcripts and articles in one click → How Codex auto-processes everything you save (no manual filing) → The Agents.md file — the secret prompt that runs the whole system → Setting up cron jobs so your wiki builds itself overnight → The 9 AM Slack "morning brief" Matt gets from his own wiki → Building a personal networking CRM (remember every conversation you've ever had) → Competitive intelligence: tracking sitemaps to catch new posts from OpenAI, Anthropic & Google before anyone else → Codex + Chrome plugin for AEO audits, ad testing, and product marketing audits → Daily journaling that cross-references everything you've ever saved → Why this is the most popular non-coding use of Codex right now 🎙️ Hosts: Kipp Bodnar & Kieran Flanagan 👤 Guest: Matt Wolfe — creator of Future Tools, co-host of The Next Wave ⏱️ CHAPTERS: 00:00 — Karpathy's viral tweet kicked this off 01:00 — What Andrej Karpathy actually said (and why 20M people saw it) 03:00 — How the LLM finds connections you didn't know existed 04:00 — Where to start if you're not a developer 05:00 — Obsidian explained: the free markdown app at the center of everything 06:00 — Auto-generated topic pages: how the cross-linking actually works 07:00 — The Chrome extension that clips YouTube transcripts in one click 08:00 — Codex: how it processes everything in the Raw folder 09:00 — The Agents.md file — the prompt that runs the whole system 10:00 — Setting up automations: your wiki builds itself overnight 11:00 — Live demo: getting AEO strategy out of your own wiki 12:00 — What Codex actually is (vs. ChatGPT) and how to install it 14:00 — How free plans, $20 plans, and Pro plans differ for this workflow 15:00 — Plugins: Gmail, Calendar, Drive, GitHub, Slack, Notion access 16:00 — "Skim my inbox and respond based on my calendar + wiki" 17:00 — The 9 AM Slack morning brief Matt gets from his own knowledge base 18:00 — Personal networking CRM: never forget a conference conversation again 19:00 — Proactive AI: why the future is agents that come to you 20:00 — Competitive intelligence with sitemap-watching agents 21:00 — How Matt sees every new OpenAI / Anthropic / Google post the moment it ships 22:00 — Codex + Chrome for AEO audits, ad testing, product marketing 23:00 — Daily journaling that cross-references your entire knowledge base 25:00 — Where this is going: from single-player to team second brains 26:00 — Why books should ship as markdown files 27:00 — The 15-minute version: Karpathy's GitHub starter that builds itself 📺 Subscribe to Marketing Against the Grain for weekly episodes on AI, growth, and the future of marketing. #SecondBrain #Codex #Obsidian #AIWorkflow #Karpathy #AITools #MattWolfe #MarketingAgainstTheGrain #ProductivityAI #PersonalKnowledgeManagement #AIForMarketers #AEO #AIAgents Host Links: 📲Kipp Bodnar, https://twitter.com/kippbodnar 📲Kieran Flanagan, https://twitter.com/searchbrat ‘Marketing Against The Grain’ is a HubSpot Original Podcast // Brought to you by The HubSpot Podcast Network // Produced by Darren Clarke. About the Show Kipp Bodnar, HubSpot’s CMO and Kieran Flanagan Hubspot's SVP of Marketing, lead you down the rabbit hole of marketing trends, growth tactics and innovation. On the way you’ll pick up undiscovered strategies to give you that slight edge for success. These are not your typical twitter thread regurgitated marketing tactics that everyone is doing. These are new methods, with unfiltered examination of successful fresh ideas.