Title: The Unreasonable Effectiveness of Recurrent Neural Networks
Author: Andrej Karpathy
Published: May 21, 2015 (Blog post)
Link: Read the blog post
🧵 In 2015, Andrej Karpathy did something unusual: he trained a simple neural network on character-by-character text data—no words, no grammar rules, just raw sequences of letters—and let it try to write stuff.
What came out was weirdly brilliant.
His model, an RNN (Recurrent Neural Network), could generate eerily realistic Shakespearean verse. It could mimic LaTeX syntax. It could produce fake Linux source code that looked plausible to the untrained eye.
And it learned all of this just by watching patterns in characters. No understanding. No reasoning. Just... repetition and probability.
The point? Even “dumb” models, when given the right structure and data, can do smart-looking things. And that realization helped shift how we think about language generation—even before the transformer era.
📌 Why This Post Still Hits
✍️ It was one of the first viral AI explainers—smart, visual, and wildly readable
🤖 Showed that pattern-matching alone could go a very long way
📜 It’s a cultural touchstone in deep learning—ask any researcher and they’ll know this post
🎁 Bonus: See It In Action
Karpathy's blog post includes numerous examples of the RNN's output across different datasets. It's a fascinating read that offers a glimpse into the early days of neural text generation.
👉 Read Karpathy’s full blog post
🎧 Podcast Note
My podcasts are produced using the “Audio Overview” feature in Google NotebookLM. It’s an incredibly helpful tool for breaking down complex topics into something you can listen to on the go. Each day, I create a new “notebook” to explore the paper’s key ideas, and the audio is generated from that.
You’ll hear two AI-generated hosts. They usually do a great job presenting the information in a friendly, accessible way—but they’re not perfect. Sometimes they talk a little too fast or dive too deep, like a human getting overly excited about their favorite subject. Or, sometimes they giggle- unnecessarily- or insert random noises. And today? They struggled with how to pronounce Andrej.
Like the technologies we're exploring in these papers, the podcast voices are both a breakthrough—and a work in progress.
🧠 Essential Vocabulary
RNN (Recurrent Neural Network): A neural network that processes sequences one step at a time, carrying information from one moment to the next (like memory).
Character-Level Modeling: Training the network to understand text one letter at a time, instead of using whole words.
Sampling: Generating text from a trained model by letting it “guess” the next character over and over until a sentence forms.
Overfitting: When a model memorizes training data instead of generalizing from it. (Some of the generated text looked almost too real.)
#TheWolfReadsAI #RNN #AndrejKarpathy #AIExplained #DeepLearning #MachineLearning #NeuralNetworks #TextGeneration #CharacterLevelModeling #AIHistory #DeepLearningwiththeWolf
Share this post