The possibility that this is some kind of set-up has crossed my mind.
In fact, the possibility had never once crossed his mind.
That possibility never even crossed my mind, and it should have.
The possibility of that happening to her hadn't crossed his mind.
The possibility that anything of the sort could happen had never crossed his mind.
The possibility of not trusting him hadn't crossed her mind.
The possibility that he might never have the chance simply did not cross his mind.
The professor looked startled, as if the possibility had not crossed his mind.
The possibility of the jack play from ace-jack-small did not cross his mind.
That possibility had never even crossed his mind before now.