Is your imagination getting the best of you, or could it be something serious?
Or was he only letting his imagination get the better of him?
He tried not to let his imagination get the better of him.
When your imagination got out of control, it wasn't good news.
He felt that his imagination was getting the better of him.
Perhaps he'd let his imagination get the better of him.
He was letting his imagination get the better of him.
"I always said an imagination could get women into trouble."
Maybe I was letting my imagination get the best of me.
He didn't like this place; perhaps his imagination was getting the better of him.