a society that seems to thrive on the unexpected とはどういう意味ですか?

What does " a society that seems to thrive on the unexpected" in the 4th paragraph mean?

Modern Watch Found in Ancient Tomb

This may be the perfect unsolved mystery, if you are a Dr. Who fan that is. A few years back, in 2008 to be precise, archeologists in China were excavating an ancient tomb in Shangsi County that dates back to the Ming Dynasty and is roughly 400 years old. While attempting to remove the tomb, a piece of rock dislodged and fell to the ground.

When one of the archeologists picked it up and began examining it, the true mystery of the tomb began to emerge. Not a rock at all, the very small article turned out to be a Swiss watch that couldn’t be more than 100 years old. The watch, sized to fit on a woman’s finger much like a modern ring, stopped running at 10:06 and though caked in dirt, it was still easy to make out the word “Swiss” imprinted on the backside of the watch.

The mystery continues to build as archeologists believe that the tomb where the ring was found was undisturbed and that they were the first to open it. Also confusing is where would this ring have come from? The watch has created many more questions than can be answered, but as scientists do, they keep asking.

Who would have wanted to plant an article here? Could it have been washed here by heavy rains? Is it an elaborate hoax by the archeologists involved in the dig, or possibly a terrible prank played out on a society that seems to thrive on the unexpected? We may never know the answers, but we can be certain as long as it’s a mystery, someone will be investigating it.