I remember learning swimming when I was a child. After a few days of paddling and prancing in the water, I began to leave the side of the pool for a few brief seconds and come back again. Longer periods of side-holding-abstinence followed, but still for short periods of time. The side on the other end of the pool seemed too far away to risk it.
Eventually, an experienced adult swimmer took me to the middle of the pool, and simply released me. I almost drowned, but fought against the water furiously, struggling to stay afloat, and at the same time, trying my best to reach the side of the pool again.
Conclusion: I could have learnt swimming on my own, if I had the courage to reach across for the other side.
As Homo Sapiens, we evolved on the ground. We feel safe when we’re on the ground. Our language reflects it — groundwork, “swept the ground from under my feet”, “ground reality”. Soldiers “hold their ground” against an enemy. A defendant “holds his ground” in the trial. “Grounds for action”, “Grounds for suspicion”, and so on. (By the way, ever wonder how that which refers to the round Earth which goes round itself is “g-round”?)
Air-sickness, sea-sickness, fear of heights, fear of flying, etc. are all reiterations of this plain, simple, fundamental truth.
Only exceptional humans have the sagacity to embark on voyages when the “other side” is not just invisible, but unknown. Columbus is one of the most famous of such explorers, who sailed for India, and discovered the US.
“Buzz Aldrin stressed that planetary exploration will only begin when mankind reconciles itself to the prospect that explorers may not return to Earth.”
What a frightening thought! Just like reaching that other side of the pool.