The familiar warning greets visitors at London's train stations and is as famous as Big Ben or the queen. Look at the souvenir stalls and you'll know I'm not lying. There are more "Mind the Gap" T-shirts, coffee mugs, and key chains than those featuring all the royal family put together.
London's transport system, especially the Underground railway with its Tube stations, is one of the quickest ways to travel around the city. If you're a tourist, all you need is a travel card and a Tube map, filled with colorful lines, to get around. It is that simple.
Londoners say that their trains are dirty and overcrowded. They say that at peak hours, it is difficult to get into a car or find a place to sit. On some days, they say, even standing space is at a premium.
As I stood at the platform one day waiting for the Tube to come through the tunnel, I couldn't help laughing at these complaints.
"Londoners are so funny," I thought with a slight grin, hoping no one noticed. "They think that this is crowded! How would they survive back home?"
"Back home" is Mumbai (formerly Bombay), the heart of India. You may have heard stories of the crowds, the noise, and the chaos. But unless you have experienced train travel there, you have not lived life. That's possibly a good thing, because – the joke goes – if you're not an old hand at train travel there, you may not have much of a life left.
It's true that Mumbai has one of the best transport systems in the world. There are trains and buses running late into the night. The trains are (mostly) on time and run like clockwork. More than 3,000 trains each day carry more than a million commuters into and out of the city.
Still, the thought of getting into another train in Mumbai makes me break out in a sweat. I traveled for many years by train, wondering each time if I would reach home alive that evening.
"What an exaggeration!" I hear you say.
Picture this: It is 7:55 a.m. I am waiting for the 8:03 train, which will take me to the other end of the city where I work.