It’s that time of year again. Some of my most vivid memories of Vietnam involve floods: back in the early days, picking my way (in high heels and a skirt) through thigh-high water to the old Vietnam Economic Times office in Hanoi; riding a motorbike through a city transformed into a giant waterpark; getting stuck in a newly-formed lake in a just-out-of-the-shop Mercedes, water lapping against the doors and the car rocking like a boat, when I was seven-months pregnant…