Why is OnItemSelectedListener only called when an item changes, but not on every user selection?

I'm using spinner controls in an Android application, and I handle user selections via an onItemSelectedListener() method. This seems to work okay when a different selection from the current one is made. I would like, under certain conditions to reset all spinners to default values and ensure that onItemSelectedListener() is called for all.

Is it part of Android's semantics that onItemSelectedListener() is only called when user selection changes. Is there a way to force onItemSelectedListener() to be called?