Here’s a funny detail: You are charged based on where you enter and exit. If you forget to tap out? You’ll be charged the maximum fare for that zone. That’s like getting a parking ticket for forgetting to blink.
Also, the Tube map is a lie. It’s a diagram, not a real map. The price zones are based on a different, invisible map. It’s a conspiracy of circles.
And finally: A single journey on the Waterloo & City line costs the same as a journey on the Central line. But the Waterloo & City line is only two stops long. You pay the same for 2 minutes of travel as you do for 40 minutes. Logic? We don't know her.