There was no written language, so he probably pulled out his hollow log, drummed some impressive beats and impressed his homies with song about shit-death-berry that everyone remembered and repeated.
...or his song was shit and nobody cared till the next poor sod shit himself to death.
What I don't get is how ancient humans figured out more complex stuff. Like neanderthals learned how to make a glue to hold their weapons together. It was probably a simple method, like this article talks about, but it still took a lot of planning and also a lot of basic reasoning before trying it themselves if it was even something that could be done.
People walked around for around ~300.000 years before inventing agriculture. That's a lot of time to find out things by accident. We learned about antibiotics by accident. I'm sure also stumbled upon many inventions by pure luck.
Caveman were smart. As smart as we are. Average person is not going to invent electronic watches but there's always this 1% that's more curious and intelligent that will experiment and discover things.
Combine this and you have 300.000 years of very slow but steady progress fuelled by chance discoveries and occasional geniuses.
Oh I'm certainly aware of the second part. It still astounds me that they were able to figure out things like that without just observing the natural world. Here's another example, although it may not apply to the early agricultural world because I don't know when it was first cultivated. Who figured out that the leaves of rhubarb were poison and the stalks are only edible with further processing? According to Wikipedia, it's been cultivated for at least 1800 years. How do you figure out, "well, this is making people sick, but what if we just ate the stems but cooked them a whole lot first?"
The thing that bums me out is how much human potential gets wasted. Like how many wicked smart kids with the potential to cure cancer or make fusion viable or whatever never got a chance to realise that potential cos they didn't have access to the education to realise that potential cos systemic inequality or racism or colonialism or just bad luck.
I imagine a lot of boredom (besides staying alive), helps finding out stuff. I can also imagine, that they had basic roles in a group, where people were designated "mess around with stuff and discover things, aka proto scientists"
I'm sure that's a big part of it, but it still amazes me the things they figured out how to achieve artificially, especially when they had no natural analogue. Like who figured out how to brew beer?
Very rarely are things lethal like that. Poison edibles tend to taste awful, and if you start with a small amount you will learn whether it makes you sick.
Now mushrooms on the other hand? No idea how they figured it out.
I find it pretty amazing how someone figured out how to make cassava edible. It's got enough cyanide to kill you unless it goes through some complex process of mashing and boiling. Who thought to themselves "this killed Greg, but maybe it'll be delicious if I boil it for a little longer"?
Necessity is the mother of invention. One day somebody was just that hungry, a cassava plant was available, experimentation ensues, bam staple crop. It's not that huge of a leap though. Most societies have some kind of root or tuber food, and once you've got the idea that roots and tubers can be food it's not a huge stretch to go looking for others. Pretty much all of them have to be cooked at least to be edible and palatable.
If you simply MUST eat strange plants, test them first by crushing a berry/leaf and rubbing the juice on your skin. If you get any discoloration, blistering, etc, then you will NOT enjoy eating it.
Humans more than likely instinctively knew which foods were safe the same way their genetic ancestors did. Since humans evolved alongside other similar species they would share similar instincts on what to look for in safe to eat vs not safe to eat foods.