To be the first human being to bring light into a place that has never had light, and to see what's there. Millions of people may come after me, but I can say I was the first. Probably finding new cave. Cavers exploring in Tennessee have now found over 7,000 caves in our state and we usually find about 300 new caves a year. The days of walking up a hill and seeing a large cave entrance are gone.
Most new caves have small entrances that require some work to enter.
In caves that have been known for some time, it is obviously a challenge to find new cave. You might notice a passage about 50 feet up a mud-covered rock wall. Modern caving techniques can be applied toward the problem, but every problem has a unique solution. Finding that solution is both a mental and physical challenge.