Even though we have all of these techniques and we're learning more every day, our understanding of all that has happened is very, very incomplete. And even more, it constantly gets challenged the more we learn. There are things that very serious people believed 50 or 100 years ago that we have now proven to be false. And things that we now take very seriously, it's likely that in 50 or 100 years, people might prove some of that wrong. So history, even though it's about the past, it is constantly evolving. We're constantly learning more. And we should have a very solid humility about what we know and what we don't know.