This seems to beg the question of what caused agriculture to appear. Although given that it did appear, your explanation seems like a plausible explanation of how it spread and led to the rapid progress we have seen since.
A boring answer to this question is that it was simple incremental changes driven by random mutations and natural selection (eg. evolution). For example, we might have started to occasional plant the seeds of plants as we found them, which could become us regularly doing so. Then we might have started moving the seeds to more central locations, and eventually arrive at agriculture as we know it today. These adaptations may have started before homo-sapiens. If it happened long enough before (so that there is another species with a common ancestor that did this), we could check this by looking for agricultural tendencies in species related to us (If anyone is aware of research on this hypothesis, please post).
A more interesting hypothesis is that agriculture was the result of an abiotic change. Instead of gradually developing agricultural tendencies, we 'immediately' became agricultural following some other event, such as a change in climate. This seems to be consistent with my understanding of climate history, which puts us in a relatively short window of nice climate.
10,000 years ago is the end of the last ice age, before which climates were shifted, sea levels were lower, and most of the land humans tend to like to live on (near sea level) are now deeply submerged.
We think agriculture and city-building started around that time, but it's possible we just haven't found older evidence because it was destroyed when the ice age ended and sea levels rose.
It seems incredibly arrogant to me to think that our ancestors, who were virtually identical to us much of those million+ years, required at-minimum hundreds of thousands of years to figure out what seeds are and how to make them grow. These are people who knew how to live off the land and were far more familiar with plants and animals than most of us could dream of being. These people invented astronomy, art, religion, clothes, tools, fire. They'd notice that plants produced seeds, that seeds wound up on the ground, and that new plants grew where the seeds fell.
I don't buy the atlantis "they're all under the sea" theory at all. We are expected to believe that they only built cities by the coast and none at all along rivers or round lakes? None of these civilizations spread to areas where the sea level has not risen so much? Far too contrived for my tastes.
Il flip your arrogance accusation around. These people developed agriculture and even cities tens of thousands of years ago, yet none of them managed to put together a sustainable survivable civilization? None of them managed to go from basic agriculture to even slightly more advanced agriculture that would have launched them on the track to specialization, even given hundreds of thousands of years in which to try? Why not? What was wrong with them?
To a hunter-gatherer, which is a nomadic lifestyle, cultivation in a fixed area for long enough to both sow and later reap a crop is not at all obvious.
I'm not completely convinced that they were genetically identical to ourselves, we used to evolve quite fast, and faster still after we developed agriculture.
Anyway, if you look at tribes native to the America, about all of them knew about agriculture (it's in their culture), but not all established an agricultural society. What we are calling "developing agriculture" probably is a much more complex phenomenon, with several different (near) contemporary developments, and probably none of them was learning that plants grow from seeds.
* Ok recent humans certainly were similar, and agriculture could probably have appeared a few thousand years earlier, I'm not sure we can extend that to hundreds of thousands, or maybe even tens of thousands.
Climate change is the working hypothesis at the moment. Specifically, general drought/desertification that drove the people at the origins of agricultural technology to a few great river valleys (notably the Nile and the Indus).
"Fungus-growing ants practice agriculture and have been doing so for the past 50 million years according to research published in the Jan. 17 issue of Science. These ants not only grow fungus gardens underground for food but also have adapted to handling parasitic "weeds" that infect their crops."
Nice, but fungus is not a plant strictly speaking "[..] These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, protists and bacteria. [..]" [1]
Which leads to an off-topic question: Is mushroom cultivation considered as agriculture?
A boring answer to this question is that it was simple incremental changes driven by random mutations and natural selection (eg. evolution). For example, we might have started to occasional plant the seeds of plants as we found them, which could become us regularly doing so. Then we might have started moving the seeds to more central locations, and eventually arrive at agriculture as we know it today. These adaptations may have started before homo-sapiens. If it happened long enough before (so that there is another species with a common ancestor that did this), we could check this by looking for agricultural tendencies in species related to us (If anyone is aware of research on this hypothesis, please post).
A more interesting hypothesis is that agriculture was the result of an abiotic change. Instead of gradually developing agricultural tendencies, we 'immediately' became agricultural following some other event, such as a change in climate. This seems to be consistent with my understanding of climate history, which puts us in a relatively short window of nice climate.