[haberman]

> Also, why is it ridiculous to describe execution time as "time complexity"?

It's unnecessarily different than the normal definition of "complexity." When you say "complex" in normal conversation, you mean "complicated" or "hard to understand." You would never say "the time complexity of getting to the airport is 30 minutes."

It also begs the question. Wrapping your head around the idea of asymptotic complexity is the hard part of understanding big O. Defining big O in terms of complexity doesn't help if you don't understand the concept of asymptotic complexity yet.

I think the best way to explain this, by far, is with a graph.