Right now, you're dozing comfortably over the span of several seats, and that's fine. The train appears relatively empty, so rock out with your socks out, bro.
But any minute now, your oneiric reverie will meet its abrupt end. The first wisps of consciousness will slowly wend their way into your dreams, and before you know it, you'll realize you're not a stowaway on a British naval ship at all, but a shoeless schmuck about to miss your stop (Delancey).
Here are a few etiquette notes for how to comport yourself in the coming horrible moments:
Please keep your agonized howls at an "indoor" volume. Yes it's late, but everyone else on the train is trying to doze/dry hump each other in peace. The damage to their eardrums will be nothing compared to the damage done to your face once it connects with that steel handrail at a high speed, but let's try to keep the pain contained to just you, OK?
Speaking of "containment," let's talk briefly about blood. The moments after you've smashed your face will be confusing for everybody—blood will be everywhere, you'll be jumping around, and for a few ghastly seconds, the thought on everyone's minds will be "there is a gunman on the train, he is shooting, he is coming for me next." As the sole party responsible for the grisly forthcoming scene, it will be important for you to put your personal anguish aside for a second and reassure your fellow passengers that they are not in harm's way. Nothing is more reassuring than a bleeding, shoeless man screaming "STAY CALM, EVERYTHING IS FINE." Fact!
Please—pick up your teeth. Oh god, your teeth are going to be everywhere, scattered all over the floor like sunflower seeds. The MTA works hard every day to mop up the trash and bodily fluids its patrons deposit with vigor all over the subway. You don't want to be the oblivious jagoff making their lives harder, do you? Picking up your teeth will take only a few seconds, and will save everyone a lot of time and trouble. Pretend they're chip crumbs! Which, admittedly, you won't be able to eat for a long, long time.
And finally, please remember to take your shoes. Someone might trip over them, and we don't want another incident like yours on our hands, now do we?
Thank you very much for reading, and we wish you a hasty and full recovery.