what does "returning"and "witty memo"mean?
【O'Brien heard the President muttering furiously, “Her winter clothes!” and asked sotto voce, “What's the story on the weather?” “McHugh must have averaged it out,” O'Donnell whispered. 'Til tell you later.” But Kennedy's spirits were returning. Holborn handed him a witty memo from McGeorge Bundy, requesting a two-week vacation at the end of January. He grinned and scrawled across the bottom of it, “Fine—I think it's time I left myself. JFK.”】
1.does "spirits were returning" mean "calm down"?
2. what is witty memo?
3.does "I think it's time I left myself" mean "I think it's time I am on my own?"or "I think it's time I was left alone"
"I think it's time I left myself"=i think it's time I take a two-week vacation, too.