Fear of that which is not, is immediately re-enforced when the idea is sought after for its possibility...
Checking if it can be possible... as we check our thinking about it, we hold it - this idea.
But because the idea now is (as we are holding it) this makes the "that which is not" now a that which is... a "that which was not, now is."
...if only as the idea, it now does exist.
When ideas scare you beyond an easy recovery, you indeed go too far.