Extra Virginity

What makes great olive oil? What makes it poor? Although I'd love to answer those questions with an answer that I could bring to the store and use, I didn't end up with a satisfactory answer. The taste and smell notes that make a oil great are elaborated on, but are tricky to understand without being there. A more useful exploration into olive oil would be finding a local place to hear about olive oil from someone who can be a guide to understanding the difference between lamp oil (which is what is in many supermarkets) and real extra virgin olive oil.