Hi nhah;.. children have imaginations which in the context of which you speak are not facts because as a child the truth of the imaginary thoughts they have are not known to them until the developing brain begins to reason ie they have not reached the stage of properly discerning for themselves what a fact is.
Thus imaginary friends, santa claus, fairies etc may seem real to them but can only be accepted as facts if reasoned upon ie to know why it's a fact.
Therefore you as an adult may say what is in the childs mind eg ' moley ' is a fact to them but that reasoning is precisely because you are an adult.
It is not the reasoning of the child therefore cannot be a fact.
Best wishes.