Although maggots have very simplified nervous systems, it's been discovered that those babies can still undergo conditioning.

You can actually train a maggot to associate an aroma with food, in fact, a research group in Germany managed to train a maggot without ever having to expose the fruit fly larva to food. How'd they do it?

They manufactured memory.

How exactly? Well you'd have to pardon me for a bit, as the following will be a bit technical.

Electrical activity in nerves is basically a matter of ions moving in and out of the cells, and the flow of these ions are controlled by specialized proteins called ion channels. The controlled opening and closing of these channels is what allows electrical signals to propagate along nerves. Here's where "memory" kicks in. Repeated signals can modulate a cells response, higher frequency, and more chances of "memory".

They took advantage of an ion channel from a single-celled organism that can be opened by exposure to blue light. Put it in a nerve cell and the cell will fire a signal when exposed to light of the right wavelength.  They confirmed that, when this channel is expressed in the nerves that control muscles, exposure to blue light would cause the maggot to twitch - the light became the substitute that activated these nerve cells.

After several rounds of coordinated exposure to light and an aroma, the maggots learned to associate the smell with discomfort, even though they had never been exposed to any uncomfortable situations.

Now, that scientists have a better understanding of memory at cellular level, even manufacturing memory in maggots, Imagine what they could do to people in the far future, or even with machines with silicon neurons... C'mon say it with me people....

...I know kung fu.