This is a practical tour, not a build: a walk through how to actually use commercial LLM products as of early 2025, illustrated entirely with the presenter's own daily queries across ChatGPT, Claude, Gemini, Grok, Perplexity, and NotebookLM. By the end the viewer has a mental map of text chat, reasoning models, tool use (search, code execution, deep research), file and multimodal input/output, and the quality-of-life features (memory, custom instructions, custom GPTs) that separate casual use from power use — plus a habit of treating every model output as a probabilistic first draft to verify, not a fact.
The model as a zip file. Everything starts from one mental image: talking to ChatGPT means streaming tokens into and out of a fully self-contained neural network, with no calculator, browser, or tools by default. Pretraining is described as compressing the entire internet into a lossy, probabilistic "zip file" — for a trillion-parameter model, roughly a terabyte — by training it to predict the next token in web documents; this is expensive (tens of millions of dollars, months of compute) and infrequent, which is why models carry a knowledge cutoff. Post-training then swaps in human-written conversation data to give that same network the style of a helpful assistant — attaching, in his words, a smiley face to the zip file. A worked example: asked about caffeine in an Americano, the model's answer (63mg) is trustworthy mainly because the fact is common and unlikely to have changed, not because the model is authoritative. Practical advice follows directly: start a new chat when switching topics, since irrelevant tokens sitting in the context window both distract the model and slightly slow and raise the cost of generation; and always check which model and pricing tier you're on, since free tiers often mean a smaller, dumber model (GPT-4o mini vs. GPT-4o, Claude Haiku vs. Sonnet) without saying so.
Thinking models. A third training stage, reinforcement learning, lets a model practice on large sets of math and code problems and discover its own effective thinking strategies — backtracking, revisiting assumptions — resembling human inner monologue rather than anything a labeler could hand-write. He illustrates the payoff with a real bug: his gradient check was failing, and non-thinking GPT-4o's advice missed the actual issue. Switching to o1 pro ($200/month tier), the model thought for about a minute and correctly identified a parameter-packing mismatch. He replicated the same prompt across providers: Claude 3.5 Sonnet solved it without any dedicated thinking mode, Grok 3 solved it, and DeepSeek R1 (run through Perplexity, which surfaces its raw chain-of-thought) worked through the bug over several minutes before also finding it. The takeaway is to reach for a thinking model specifically for hard math/code/reasoning problems, since it adds little for something like travel advice, and to check whether a given provider even ships one (Anthropic did not, at the time of filming).
Internet search. Since the zip file's knowledge stops at its training cutoff, fresh questions require the model to emit a special token that triggers a live web search, pulling page text into the context window before answering. His running example is checking the release date of a new White Lotus season: without search, no model could know; with it, ChatGPT, Grok, and Gemini 2.0 Flash answered correctly with citations, while Claude 3.5 and Gemini 2.0 Pro lacked the integration entirely at the time. He treats Perplexity as his default search tool for anything time-sensitive or niche — market holidays, filming locations, product rumors, "what's this tweet storm about" — always checking citations since the underlying answer can still be hallucinated.
Deep research. Combining search and extended thinking, this ChatGPT Pro feature (then $200/month, with Perplexity and Grok offering rough equivalents) spends up to tens of minutes issuing many searches and reading many sources before writing a long, cited report. Asked to research a longevity-supplement ingredient, ChatGPT returned a report citing 27 sources after five minutes of work; a request for a table of U.S. LLM labs and their funding, by contrast, came back with real errors — xAI missing entirely, Hugging Face and EleutherAI wrongly included — underscoring that even a heavily-sourced report is a first draft requiring independent checking, not a finished answer.
Working with documents. Beyond search, models can take concrete documents directly into their context window via upload. He demonstrates dropping a 30-page biology paper (on a DNA foundation model called Evo 2) into Claude and ChatGPT to get summaries and ask questions, and describes routinely reading books this way — pasting chapters of Adam Smith's 1776 Wealth of Nations into Claude alongside the reading, asking for a chapter summary first and then following up with questions, which he says dramatically increases retention, especially for unfamiliar fields or old texts. No tool yet makes this seamless, he notes; it's still copy-paste back and forth.
Code execution and Claude artifacts. Giving a model a Python interpreter lets it write and actually run programs rather than guess arithmetic in its head — demonstrated by a large multiplication where Grok 3 hallucinated a wrong answer while ChatGPT and Claude wrote code and got it right. In "Advanced Data Analysis," ChatGPT is shown researching and plotting OpenAI's valuation history, fitting a trend, and extrapolating to 2030 — where it silently assumed a missing 2015 value and then reported $1.7 trillion for 2030 when its own code, once reprinted, actually computed roughly $20 trillion, a discrepancy only caught by rereading the code. Claude's separate "artifacts" feature is shown generating a working flashcard React app from pasted text and, more usefully in his own workflow, turning a book chapter into a Mermaid-diagram concept map — both cases of the model not just answering but building and running a small interactive tool inline.
Vibe coding. For real software work he leaves the browser entirely for Cursor, an editor built around Claude 3.7 Sonnet that has full context of a project's files. A short live demo has Cursor's "composer" agent build a Tic-Tac-Toe app from a five-sentence request, then add a confetti effect and a victory sound entirely on its own initiative, pausing only to confirm running a shell command — what he terms "vibe coding," where you mostly supervise rather than write code, with the fallback of reading and editing the files yourself when needed.
Audio, images, and video. He distinguishes "fake audio" — speech transcribed to text and back via separate models (roughly half his queries use this, via ChatGPT's mic button or the system-wide app SuperWhisper) — from "true audio," where speech is tokenized like text and handled natively inside the model, demonstrated live with ChatGPT's advanced voice mode switching between Yoda, pirate, and storytelling registers, and with Grok's more unfiltered persona modes. NotebookLM gets a similar demo generating a full spoken "podcast" discussion from an uploaded paper. On images, the same patch-based tokenization lets him upload nutrition labels, blood test screenshots, a toothpaste ingredient list, and a meme for explanation, generally transcribing to text first to verify the model read values correctly before asking follow-ups; DALL-E 3 handles image generation, and advanced voice's camera mode lets the model narrate what it sees live.
Quality-of-life features. ChatGPT's memory feature saves short text notes across conversations (e.g., a stated opinion on "peak Hollywood") that get silently prepended to future chats, which he says has made recommendations noticeably more personalized over time; custom instructions set a persistent tone and background (he uses his for a preferred formality level when practicing Korean); and custom GPTs bundle a reusable few-shot prompt, illustrated with three he built for Korean study — a vocabulary extractor, a detailed phrase-by-phrase translator, and an OCR-plus-translate tool for screenshotting hardcoded subtitles — each just a saved prompt with examples rather than anything architecturally new.