The average human brain—weighing in at a scant three pounds—has, according to one estimate, upward of 100 billion neurons that connect with one another via some 100 trillion synapses.
A hundred trillion? Wow. You learn something new every day, right?
But wait. Was that really learning? Or was it just a bit of trivia you're likely to forget as quickly as you read it? What, exactly, is learning?