One word: nightmare.
You may be really early for work. It doesn’t matter. It will always find a way of making you late: a faulty train, problems on the tracks, signal failure, person under the train, you name it.
I have always tried to face the Tube with a smile, but trust me when I say this line will challenge you any chance it gets.
Some of the things I’ll do: read the newspaper or a magazine, listen to music or an audiobook, read a book, write a post in my notebook (such as this one), play a game on my phone. And smile. Even if it’s just to yourself. There are so many worse things in life.