Introductory it as Subject
2.3 it V to n whThe verb is followed by a prepositional phrase beginning with to, and a wh-clause. The prepositional phrase always indicates a human being. The prepositional phrase is the prepositional Object.
|it||Verb group||to||noun group||wh-clause|
|It||came||to||me||what Pop had forgotten.|
|It||didn't matter||to||her||what happened to us.|
Two of the verbs with this pattern indicate that an idea occurs to someone.
It occurred to me how truly blessed we are to live in a town that's just chock-full of so many interesting races, creeds and colors.
There is one other verb with this pattern.
It doesn't matter to them whether or not they sell your product.