Nerve endings. That’s what it all comes down to. Billions of rooted synapses, like trees entwined in erratic soil. Lightning strikes every millionth of a second, the charges scattering across the gaps and down a spinal braid.

Concepts of memory tend to reflect the technology of the times. Plato and Aristotle saw memories as thoughts inscribed on wax tablets that could be erased easily and used again. These days, we tend to think of memory as a camera or a video recorder, filming, storing, and recycling the vast troves of data we accumulate throughout our lives. In practice, though, every memory we retain depends upon a chain of chemical interactions that connect millions of neurons to one another. Those neurons never touch; instead, they communicate through tiny gaps, or synapses, that surround each of them. Every neuron has branching filaments, called dendrites, that receive chemical signals from other nerve cells and send the information across the synapse to the body of the next cell. The typical human brain has trillions of these connections. When we learn something, chemicals in the brain strengthen the synapses that connect neurons. Long-term memories, built from new proteins, change those synaptic networks constantly; inevitably, some grow weaker and others, as they absorb new information, grow more powerful.

The human mind is itself a miraculous machine. I am writing right now, but I have no idea how this is happening. I know that my brain is composed of a cerebrum, a cerebellum, and a medulla oblongata, but these are just words. I know that electrical impulses are involved somehow, but that is about the extent of my understanding of the mechanics. And while I at least have an intuition as to how an airplane works, I really have none with respect to my brain. Frankly, lots of what appears on my computer screen is as much a surprise to me as it is to you. I certainly never expected over my oatmeal and English muffin this morning to be writing about Bernoulli's principle today. For that matter, I have no idea why I like English muffins. But I do.

But if you tell folks you're a college student, folks are so impressed. You can be a student in anything and not have to know anything. Just say toxicology or marine biokinesis, and the person you're talking to will change the subject to himself. If this doesn't work, mention the neural synapses of embryonic pigeons.