What is the point of mushrooms?

Swords & Sworcery sometimes features blinking mushrooms, of which you can carry up to three. when you use one you kind of get hallucinations and that's it.

In areas where the song of sworcery works then the areas you can click on do highlight while the mushroom effect is active - but then you can't actually do the song in the first place until the effect wears off.

What am I missing?