Open mindedness does not only mean to be open to the possibility of a supernatural reality or other seemingly paranormal occurrences. It also means to accept the notion that the unexplained doesn't always have to be unexplainable.
It's easy to get caught up, misled, misguided or to be misinformed, let alone completely uninformed. Before rushing headlong into "belief" that some unseen force is at work we must first exhaust the obvious and look closer to home for the answers. It's just the logical first step.
For those interested in studying the paranormal — ghost hunters, budding UFOlogists, and others — I must suggest you begin your journey by reading a book that will help explain the reality behind many things considered paranormal.
The book I strongly suggest as a primer for anyone persuing the paranormal as a hobby or as a serious field of research is "The Demon-Haunted World: Science as a Candle in the Dark" by the late Carl Sagan.
In this book Sagan uses science and logic to help us understand the real workings of the paranormal and the supernatural. He examines religious beliefs, belief in UFOs, supernatural beings, alien abductions, cryptozoological topics and more.
He doesn't merely dismiss these popular mysteries and beliefs. He explains the mechanics of the human nature and the very important roll our mental and emotional development plays in determining how we distinguish (or not) between fantasy and reality.
There is more to the paranormal than you may think, but the truth lies more in how we perceive our world than in how our world really is. That's not to say that things unknown can't be tapping on our attic doors or trying to contact us from distant worlds. In fact Sagan had a special place in his heart for the mysterious and wonderous, he just couldn't find enough scientific evidence to support them. He kept looking though.
He did point out that there were many wonders in our world worth experiencing. Wonders that don't require an ounce of belief, just observation and amazement.
Before engaging in the investigation of the unexplained you must throw belief out the window, that's not what it's about. Belief doesn't find the answers.
Nearly every night, just before I drift off to sleep, I spend a few minutes gazing out the window at the night sky. I hope beyond hope that a craft of unknown origin will soar past my window, aglow in bright lights, gleaming silver and pulsing with the low hum I've heard in Hollywood UFO movies. That spaceship never comes, but I still keep looking.
Openmindedness is about being open to all possibilities while looking for the truth based on the evidence at hand. No real evidence, no real mystery.