Introductory it as Subject
Other productive usesThis pattern is productive: a wide range of verbs concerned with the consequences or implications of situations and events sometimes have this pattern. For example, it occurs in clauses like It destroyed our credibility that we didn't know what was going on within our own team.
In addition there are a few fairly fixed phrases with this pattern.
It broke my heart that she could shut out my pain so easily.
He seemed less surly, more comfortable about being polite and ordinary. So it crossed my mind that I might give him another chance.
It never entered her head that their divorce would go through without a financial settlement having been made.
Most of the evidence was against him, and so it makes sense that he was found guilty.
It made no difference that we tried to talk to her, she just looked straight ahead and didn't answer us.