No, it mostly didn't, it continued (continues, as every human is continuously interlacing “training” and “inferencing”) training on large volumes of ground truth for a very long time, including both natural and synthetic data; it didn't reason everything beyond some basic training on first principles.
At a minimum, something that looks broadly like one of today's AI models would need either a method of continuously finetuning its own weights with a suitable evaluation function or,if it was going to rely on in-context learning, would need many orders of magnitude larger context, than any model today.
And that's not a “this is enough to likely work” thing, but “this is the minimum for the their to even be a plausible mechnanism to incorporate the information necessary for it to work” one.
For concepts that are not close to human experience, yes humans need a comically large number of examples. Modern physics is a third-year university class.
Either the bar of general intelligence set by humans is not very high, or humans are not "generally intelligent" at all. No third option there.
Based on... what?
On top of that, true general intelligence requires a capacity for unbounded growth. The human brain can't do that. Humanity as a civilization can technically do it, but we don't know if that's the only requirement for general intelligence.
Meanwhile, there is plenty of evidence to the contrary. Both as individuals and as a global civilization we keep running into limitations that we can't overcome. As an individual, I will never understand quantum mechanics no matter how hard I try. As a global civilization, we seem unable to organize in a way that isn't self-destructive. As a result we keep making known problems worse (e.g. climate change) or maintaining a potential for destruction (e.g. nuclear weapons). And that's only the problems that we can see and conceptualize!
I don't think true general intelligence is really a thing.