She said the first thing that came into her head.

The question that came into my head was, Is he dead?

Then he made up the first name that came into his head.

As I looked at it, an idea came into my head.

I said the first thing that came into my head.

He simply did or said whatever came into his head.

He said the first thing that came into his head.

He gave the first answer which came into his head.

At this moment a certain idea came into his head.

When I came back into my own head, he was on me.