"You'll have plenty of time to sleep when you're dead."
Said to me by a temporary co-worker some time back, after I complained how tired I was, while working 14 hour days in the midst of the busy season.
Since he wasn't full-time, he was allowed to leave by 5PM. But I couldn't say anything smarmy back to him, because he had a debilitating illness that kept him from working more than six or seven hours a day anyway. So I had no other choice except to run off screaming into the night.