fanciful
notional
indulging in or influenced by fancy
a fanciful mind
all the notional vagaries of childhood
having a curiously intricate quality
a fanciful pattern with intertwined vines and flowers
imaginary
not based on fact; existing only in the imagination
the falsehood about some fanciful secret treaties
F.D.Roosevelt
a small child's imaginary friends
to create a notional world for oneself