Ten things a few months of subway travel will teach you how to do:

1. Balance without the need to touch the dirty subway poles.

2. Pretty accurately figure out where the exact middle of the platform is.

3. Predict, based on how many people are waiting on the platform, how recently a train came, when the next one will arrive, and how crowded it will be.

4. Identify the liquids dripping from the ceiling, as between "non-toxic water," "toxic water," "safe strangely-colored goo," "unsafe strangely-colored goo," and "blood."

5. Hold a book and turn its pages even when there's barely space to breathe.

6. Not make eye contact with anyone, yet still be able to tell if they're about to lunge at you.

7. Identify subway panhandlers before they begin their speeches about Jesus, so you can pretend to be engrossed in your magazine and not have to pay attention.

8. Identify whether something on the seat is sticky or dry without having to touch it.

9. Predict which fellow patron will be falling into you when the train lurches.

10. Determine, from the subtle hints given by the conductor in his or her announcement, whether the delay causing the current stop is going to be brief ("we will be moving momentarily"), not so brief ("we will be moving shortly"), or really really long ("we will be moving as soon as we can").