The people who first invented tools had to invent inventing tools without tools.

"Let's invent a thing inventor", said the thing inventor inventor after being invented by a thing inventor.

I mean, a good enough rock can be considered a tool. Same as an antler or a bone.

That's basically what the How to Make Everything YouTube channel is about.
- They are only inventing tools. They are not inventing the concept of inventing tools.
  Still very cool and impressive
  
  Fair point. Missed an "invent" in your title 😅.

This is a good shower thought, and I'm not knocking it.
A rock is a tool. A stick is a tool. Some rocks are naturally sharp (flint and obsidian) and are different kinds of tools. Any physical object found in nature could be a tool, and other animals exhibit tool use.
Taking two different kinds of rocks and carefully hitting one with the other can improve the naturally occurring tool, and I think that's why your thought is insightful (although, not unique). Knapping isn't rocket science, and it doesn't require anything more than one of several special kinds of rocks and a second rock, but it does require skill, and that comes through practice. I don't think it was probably a deep thought to think "I could make this sharp-edged rock more useful with a little chipping," but it certainly qualifies as "inventing inventing tools."

First tool: a rock someone found
- Second tool: that same rock someone else found. But it's mine now.
  
  Third tool: I copied that rock then took that rock with my rock. Now I have two of them.

They had to invent inventing first.
- meaning they had to have a concept of inside and ventilation, which is wild. how else would they have invented in vent?
- Kinda what I was going for but I don't think I phrased it right.
- Before that they had to invent invent inventing.

This reminds me of a short story/presentation by computer scientist Ken Thompson titled, "Reflections on Trusting Trust".
It's worth reading but basically we use software to create software. We trust that the software we use to create software can be trusted. We have the source code, but that's just words on paper, it doesn't do anything. We have to use software to turn that code into software.
To light a campfire take a burning stick and apply it to the pile of tinder and dry wood. Where do you get a burning stick? Place one in a campfire.
- I like to talk about this in my CS classes. We get compiles to compile code by compiling a compiler with a compiler. It's an infinite regression problem that terminates with someone writing a compiler in assembly... Which requires an assembler to assemble... So you write an assembler in machine code directly on the processor.
  If we lost all of the currently compiled programs one day, even with the compiler source code in hand, it would be some serious work to rebuild our current tool chains.

I've never met anyone who doesn't pick up a stick or a rock during a hike. We've been gathering our own tools for hundreds of thousands of years and that curiosity and ingenuity is bone deep for us as a species.

Sure. But inventing tools doesn't require you to have tools, so it doesn't make it more impressive.