The ’80/20′ ChatGPT prompt is the fastest way to learn anything
We’ve all had that moment when you realize you’re in over your head. For me, this happened during my first briefing with a smart lighting salesman, when it became painfully obvious that I couldn’t tell a standard A19 bulb from a BR30 bulb.
Clearly, I needed help, and fast. An on-the-spot crash course, something that would give me a solid foundation of lighting knowledge before publicly embarrassing myself again. This particular knowledge crisis took place in 2019, before ChatGPT, Claude and Gemini existed. This left me at the mercy of Google, or even (gasp!) my local public library branch.
But now that we TO DO If ChatGPT and all other AI chatbots are at our disposal, there is a simple prompt that can help you go from dunce to almost any topic in just 10 minutes.
I’m talking about the “80/20” prompt, which is derived from the 80/20 rule (aka the Pareto principle) which states that 80% of the results come from only 20% of the causes. The 80/20 rule has been used in fields ranging from business (for example, “80 percent of your revenue comes from 20 percent of your customers”) to cooking. And as AI engineers quickly discovered, it can also be applied to learning new skills.
There are many versions of the 80/20 AI prompt, but here’s a common one I’ve seen floating around:
I want to learn [TOPIC]. I don’t need to become an expert, I just want a solid practical understanding. Identify the 20% most important concepts, terms, or ideas that will give me about 80% of what I need to know. Teach me these first, in simple language.
And here’s an even shorter version:
What is the 20% of [TOPIC] I should learn to understand 80% of it first?
This prompt causes the AI to prioritize the most vital 20% of a given topic, making you 80% familiar, while making it clear that you are not looking for a master’s degree. You just need basic knowledge on the subject and you need it quickly.
I tried this prompt using ChatGPT GPT-5.5 Instant for my previous light bulb puzzle and got an introduction that I wish I had back then. Here is a representative excerpt from ChatGPT’s response:
A19 = “the normal bulb”
This is the standard bulb shape used in:
- table lamps
- street lamps
- many ceiling lights
- basic wall lights
The “19” refers to the size.
If someone says:
“This light fixture takes A19 bulbs”
they mean: standard household light bulbs.
That’s it.
Phew! Not expert-level knowledge, sure, but enough to get me through my next meeting without making a fool of myself.
Then I tried something a little trickier: quantum mechanics. (I was an English major in college, so I knew less about molecules than light bulbs at the time.) Here’s a small part of what I got:
A quantum object is described by a wave function
This is the central idea.
A particle (like an electron) is not just a small ball with a set position and speed.
Instead, it is described by what is called a wave function, which encodes:
- where it could be
- what it could do
- the probabilities of different outcomes
You can think of the wave function as a “cloud of possibilities.”
Well, OK, I can kind of follow that! I’m still not an expert after reading ChatGPT’s 80/20 introduction, but at least I now have a rough idea of the Heisenberg Uncertainty Principle.
Some caveats regarding the 80/20 prompt:
- This is as good as basic AI knowledge. A massive model like Claude Opus 4.7 or GPT-5.5 will probably give you a solid 80/20 briefing on just about any topic, but a small “snapshot” model might give you a more summary answer.
- You can try basing the AI with a PDF on the subject and request the 80/20 processing based on the uploaded file. You can also ask the AI to search the web before responding.
- It’s not ideal for learning practical skills that require real practice, like painting. Instead, stick to concepts.
One last tip: Try adding a time restriction to the 80/20 prompt (e.g., “I have 10 minutes to get ready…”). This can help either expand the 80/20 response you get (months) or compress it into a smaller, more digestible package (hours).
