Today, on International World Water Day, roughly one in 8 people lacks access to safe water - and waterborne illnesses kill nearly two million every year.
Meanwhile, Japan now faces a different water threat. With radiation leaking from the Fukushima nuclear power plant, trace amounts were found in tap water in six locations, including Tokyo. One village near the plant was advised to avoid tap water entirely.
It's hard to think of something as simple as a glass of water as a luxury. I'm sure most Japanese people never did. But it's worth remembering, today and every day, that this most basic resource is also a fluid and fragile one.
That's a page from my notebook.
I'm Katie Couric, CBS News.