It's a duff reference to McCoy's line in The Voyage Home.
"Are you sure this is such a bright idea?"
"What do you mean?"
"I mean, him back at his post like nothing's happened. I don't know if you've got the whole picture or not, but he's not exactly operating on all thrusters."
"It'll come back to him."
- Kirk and McCoy, as Spock returns to duty
...is the exploration that awaits you. Not mapping stars and studying nebula, but charting the unknown possibilities of existence. - Q