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Yukti Sahu
Yukti Sahu

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From RNNs to ChatGPT: The Paper That Changed How AI Thinks 🤖

💡 “Attention Is All You Need”: The Paper That Changed How AI Thinks

So, I was just scrolling through Instagram reels when one popped up saying —

“If you really want to understand what real AI is made of, go read the paper ‘Attention Is All You Need.’”

At first, I laughed a little — I thought it was something about mental health and focus 😅.

But curiosity won. I searched for the paper, opened it, and… okay, I’ll be honest — I didn’t get even half of it by reading directly.

So, as the smart generation we are, I passed the paper to ChatGPT and said,

“Explain this to me like I’m five, but still make me feel smart.”

And wow — what came out was fascinating.

Here’s everything that paper actually means — in plain, simple English.


🌟 1. Background – What Was the Problem Before?

Before the Transformer was born, all AI models for language — like translation or speech — used RNNs (Recurrent Neural Networks) or CNNs (Convolutional Neural Networks).

🌀 The RNN Problem

RNNs read data one word at a time — first “I,” then “love,” then “pizza.”

They remember what came before using something called hidden states.

But here’s the issue — when sentences got long, they started forgetting earlier words.

And since they process words one by one, parallel processing (speed) was impossible.

📖 Example:

Sentence: “I went to Paris because I love art.”

To connect “I” and “art,” RNN has to go through the entire sentence — word by word.

That’s slow and memory-heavy.

🧩 The CNN Problem

CNNs were faster, using filters to detect local word patterns like [I love] or [love pizza].

But they couldn’t easily understand long-distance relationships — like connecting “it” and “animal” in

“The animal didn’t cross because it was tired.”

So both RNNs and CNNs were limited — they worked but weren’t great at context or speed.


⚡ 2. The Big Idea — The Transformer

Then came 2017.

The paper “Attention Is All You Need” by Vaswani et al. dropped — and it revolutionized everything.

The authors said:

“What if we throw away RNNs and CNNs completely… and just use attention?”

🧠 What’s Attention?

Attention means focusing on the most relevant parts of information.

When you read a paragraph, your brain doesn’t remember every word — it focuses on key ones.

That’s what the Transformer does: it looks at the whole sentence and figures out which words depend on which.

Example:

In the sentence

“The animal didn’t cross because it was too tired,”

the word “it” clearly refers to “animal.”

That’s what self-attention helps the model understand — without reading word by word like RNNs.


🔍 3. Transformer Architecture – The Encoder–Decoder

The Transformer is built from two main parts:

1️⃣ Encoder – The Reader

It reads the input sentence and figures out all relationships between words.

Example:

“I love pizza.”

→ It learns that “love” is strongly connected to “pizza.”

2️⃣ Decoder – The Writer

It takes that understanding and generates output, like a translation.

Example:

“I love pizza.” → “मुझे पिज्ज़ा पसंद है”

So, the encoder understands, and the decoder speaks.


🧩 4. The Secret Sauce – Types of Attention

💫 (a) Self-Attention

Every word looks at all the other words in the sentence and decides which ones are important.

Example:

“The animal didn’t cross because it was too tired.”

Here, “it” relates to “animal,” not “cross.”

Self-attention figures that out automatically.

💫 (b) Multi-Head Attention

Instead of one attention mechanism, Transformers use multiple attention heads.

Each head learns something different:

  • One focuses on grammar.
  • One on meaning.
  • Another on context.

It’s like having a group of teachers — each checking your sentence from a different angle.


🔢 5. Positional Encoding – Remembering Word Order

Since the Transformer doesn’t read in sequence like RNNs, it doesn’t know word order.

To fix that, it adds positional encoding — a mathematical way to tell the model the position of each word.

📍 Example:

“Book a flight to Delhi” ≠ “Delhi a flight to book.”

Positional encoding helps it understand that order matters.


⚙️ 6. Training Details

The original Transformer was trained using:

  • Optimizer: Adam
  • Dataset: English–German and English–French translations (WMT 2014)
  • Hardware: 8 GPUs for just 12 hours!

That’s super fast compared to RNN or CNN models of that time.


🧪 7. The Results

The Transformer outperformed every model before it.

Task Dataset BLEU Score (higher = better)
English–German WMT 2014 28.4
English–French WMT 2014 41.0

That was a 2+ point improvement over previous state-of-the-art systems — with less training time.


💭 8. Why It Was a Revolution

  • 🚀 Faster training → parallel processing
  • 🧠 Better context understanding → self-attention
  • 🔄 Scalable → the bigger the model, the smarter it gets

This paper inspired all the models we use today —

BERT, GPT, T5, Gemini, Claude, and beyond.


🎬 Real-World Scenarios

Use Case Explanation
🌍 Google Translate Uses Transformer for language translation
💬 ChatGPT, Gemini Based on advanced Transformer variants
🖼️ Vision Models (ViT) Use attention for image understanding
🎙️ Speech Models Modified Transformers for audio and text

🪄 Beyond the Paper – My Curiosity Took Over

After reading, I couldn’t stop wondering —

“How do these models now process audio and images too?”

So I asked GPT a few more questions.


🧩 How Do Transformers Handle Audio and Images?

Text was just the beginning.

Later, engineers realized they could also break images into patches (small square pieces), treat them like words, and feed them into a Vision Transformer (ViT).

For audio, they convert sound into spectrograms (visual wave-like graphs).

The same attention mechanism then learns patterns in sound frequencies — recognizing tone, pitch, and even emotion.

That’s how models like Gemini or GPT-4o can now see, listen, and respond intelligently across formats — they use multimodal transformers.


🎨 Then I Asked: “How Does AI Generate Images?”

The answer?

Through something called Diffusion Models.

They start with pure noise and slowly turn it into a meaningful image by reversing the noise step by step.

Example:

Prompt: “A cat riding a bike in space.”

The model begins with random static and diffuses backward — learning how to “denoise” it into an actual picture.

Each denoising step is guided by your text prompt, so the cat, the bike, and the space background all take shape gradually.

That’s what powers Stable Diffusion, DALL·E, and Midjourney.


🧭 In Simple Words

Model Core Idea What It Does
RNN Sequential memory Learns time-based patterns
CNN Filters + local focus Good for images and short text
Transformer Self-attention Understands global context
Vision Transformer Image patches “Sees” like a human eye
Diffusion Model Reverse noise Creates new images
Multimodal Transformer Unified input Handles text, image, audio

✨ Final Thought

That Instagram reel led me down a rabbit hole — and it turned out to be the best kind of curiosity.

From “Attention Is All You Need” to ChatGPT and Gemini, the entire AI world evolved because of that one paper.

It replaced slow, step-by-step thinking with fast, focused attention — and gave birth to models that can read, talk, see, and even imagine.

RNN walked so Transformer could fly — and now GPTs are flying rockets. 🚀


📚 Further Reading

Here are some great references if you’d like to dive deeper 👇


✍️ Written by Yukti Sahu — exploring the world of AI, one paper at a time.

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