Everyone is always so quick to offer their two cents, even if they weren't asked. Most of the time, this intrusion comes from a good place in their heart, that place where people want to offer assistance to those they love. However, the occasional piece of advice will be mistimed or misinformed, leaving you with something you're unable to use.
Divers will usually give the same reason for wanting to dive to the darkest depths of the ocean: They all want to see something fascinating. Odds are you'll encounter something under the surface no one on dry land will ever witness. However, sometimes what you see will not always be pleasant.