Traveling as a whole is usually inconvenient, tiring, and of course - delayed. But it's part of the package deal for most when it comes to the holidays. And the bookends of the experience, the expectation and the arrival, make the sludge in between worthwhile.
When you're taking mass transit it becomes a largely passive experience, lots of waiting with little action. The upshot here is that you've got a chance to carve out your own nook amid a hull of passengers. To each his/her own, but below's my longest-running playlist. It's scientifically engineered to be wistful, cozy, warm. Ideal for daydreaming while staring out a window (if you were lucky enough to snag that seat!).
Not that I have a degree to prove it, but taking this nook theory a step further I'd say it'll extend into your post-travel explorations. Be it a new city or one you visit regularly. Finding something no one else is paying attention to is an undeniable thrill. Okay, thrill is strong - but it's pretty cool to catch a building in just the right light or to see someone on their morning jog visit a national monument.
(This is the part where you realize I've tricked you into looking at pictures from my all-too-quick trip to D.C.)