Answer:
Tomorrow's yesterday. Yesterday's tomorrow. What is it?
Something you carry while singing.
Temporary evidence of where you've been strolling
Four kings of whom I am one lord. Often on deck but never on board. Though I have a large heart, I am always seen at war. During which I always wear a suit, but never a suit of armor. Who or what am I?
What can you lose that will cause other people to lose theirs too?
What is always coming but never arrives?