Protection.

This young guy was well insulated from both the cold and the world.

He had the obligatory silly wooly hat, complete with cutesy ears, over which he had clamped an impressive pair of noise cancelling headphones. Nothing was going to get to him.

And, when he stood up to get off the train at St. Pancras, it turns out he was carrying an ornate Elven sword which he tucked, Legolas style, diagonally into his backpack. 

Like I said, nothing was going to get to him