Weird. I checked with my brother too, because I remember this episode.

We both remember very specifically that the moral of the story was being afraid of something small and harmless can prevent you from enjoying anything else.

This is extremely true of fear. The other mantra I remember that also says this is from Dune (a little paraphrased): "I must not fear. Fear is the mind killer. Fear is the little death that brings total obliteration. I will face my fear. I will let it wash over me and through me. And when it had gone past, I will turn the inner eye and see that along its path there is nothing. Only I will remain."