On my last Friday in Yemen, my friend Nasser invited me to his home on the outskirts of Sanaa for lunch. We were an eclectic group. There were two of Nasser's nephews, both university students. There was also a cardiologist, a couple of ex-soldiers, a teacher and a human rights lawyer. (Naturally, we talked about Barack Obama. This is a theme in my travels. I think the only way that I'll hear less about Obama is if he wins.)

As is the custom in deeply traditional Yemen, the men ate together in the main room. The women -- who had prepared the fantastic meal of Yemeni favorites like salta, a light, savory stew served near-boiling in a crockpot -- were out of sight, eating in another room. After a week in Yemen I was accustomed to the segregation. In fact, when I met Nasser's niece a few days later, I was surprised to hear that she had been with the family at lunch -- I hadn't seen a female the entire afternoon.

After lunch the men retired to the ground-floor sitting room for the traditional male afternoon pastime: khat. For the uninitiated, khat is a green leaf that's chewed to generate a mild buzz. (Women don't chew.) It's a big deal among Somalis and in Djibouti, where I had chewed it once before, about three years ago. I found it extremely bitter and could only keep the stuff in my mouth for a few minutes before spitting it out and downing a half-liter of Coke to get the taste out.

Weak. In Yemen, they are serious about their khat, and in the afternoons in Sanaa you see nearly every man gently working at a golf ball-sized lump in one cheek. Nasser told me that I shouldn't judge khat until I'd tried the good stuff, and I agreed to give it a solid go.

He and another man handed me a couple of fistfuls of khat and taught me to discard the harder leaves, which were tougher to chew. Focus on the smaller, softer leaves, which taste better, they said. They handed me some sweet tea and a big bottle of water and I got to work.

I tried harder this time. I really focused on picking the right leaves, hoping this would help. Everyone around me was chatting in Arabic, so I slowly drifted off. A half-hour must have gone by. Maybe an hour. Something strange started to happen. I began to feel a little light-headed. I lay back in the velvety cushions and felt relaxed. There was a lot of laughter at a long story in Arabic, and I started to laugh too. I chewed some more, sipped some more water, didn't spit anything out. A couple of men asked me about the U.S. election, and I answered them. Wait, was I speaking Arabic? I couldn't tell. I kept chewing and the whole room felt like it was floating and the stories got funnier and the cushions below me felt softer and...

OK, none of that happened. I chewed for more than two hours, and nothing. No buzz, not even the hint of one. Just a sore jaw, a bladder full of water and tea, and a plant taste that I couldn't wash out of my mouth for a couple of hours. It was a fun afternoon, and the guys were great company. But I felt like I'd still missed the point.

As in Djibouti, khat in Yemen is an expensive habit for a terribly poor people. Not only is Yemen the poorest country in the Middle East, it's also one of the driest in the world, chronically short of water. When I met an official in Yemen's water department at the start of my trip, he told me that 93 percent of Yemen's water supply goes to agriculture and 40 percent of that water goes toward irrigating khat crops. Khat is literally sucking this country dry.

Then there's the social impact. When a man is chewing khat, he's not doing much of anything else. I met a couple of men who said they spent more on khat in a day than they did on food for their families.

The water official felt strongly that the Yemeni government needed to do something about khat. "It's like any drug," he said. "If it's not illegal why would people stop doing it?"

Outlawing it may not be an option -- it's part of the culture, like vodka in Russia -- and it's not as physically debilitating as alcohol, even. But this official was in favor of making it a once-in-a-while thing instead of an everyday addiction. Boys are starting to chew at younger and younger ages, he said. It's another way that women's issues are sidelined. It's a huge economic drag on a country that needs to spend its money more wisely.

And I'm pretty sure I'd feel this way even if I had gotten that buzz.