We've all experienced it, especially those working in London and other major cities. Waking up early in the morning, heading to the nearest station and sitting (or more likely standing) on a train for ages, only to be told there are delays and cancellations. By the time you've got to work you are already exhausted and you've not even opened your emails. But there comes a time in many commuters' lives where the 'F' word is said and plans to quit start whirling around inside the head. Those round the world flights get searched for, Google maps gets a workout and the calculator comes out to start working out whether it can be afforded. That's right, that once in a lifetime trip seems to be coming to fruition. But taking that step can be scary. Here's how not to do it...