When I tell people about my dad's situation, there are usually two main points that really get their attention. First, a low point, then a high point, and then comes a whole bunch of questions.

First things first: My dad is not able to swallow correctly. What I mean by that is, when he swallows, instead of going into his stomach, some of the food or liquid goes into his lungs and invariably give him pneumonia. As a result, he hasn't eaten or drank anything in over two years. Anything.

When I ask him what the last meal he ate was, he hesitates, trying to remember: "I love chicken, maybe it was chicken? I don't know."

Is there any specific food that he misses most, I ask?

"A cold glass of water," he tells me. "I see people drinking a bottle of cold water, and that really hits me."

So that's the bad part. And if you're like most people, you're probably picturing my dad in a hospital bed, shriveled up, near-death, with tubes running in and out of his body.

Not by a long shot.

So now comes the good part: My dad hasn't let this massive setback derail his daily life.

He goes to the gym, hangs out with friends, and takes the subway around New York City.

It's a normal sounding life. But...then I remember, he still can't eat or drink. Anything. And there's a good chance he will never eat or drink again.

One of the most frustrating parts is there's been no diagnosis. He was tested for everything—ALS, MS, Parkinson's—all the results were negative.

"I Took My Mouth For Granted"

So how can someone live without eating or drinking? My dad has a feeding tube inserted into his stomach. It requires a lot of maintenance, which my stepmom Francie helps out with. Keeping that hole in his stomach healthy is really important. At this point, the hole is basically my dad's second mouth, so to speak.

Every day, my dad uses what looks like a giant syringe to "feed" himself this white gooey nutritional supplement called TwoCal. It takes four or five cans a day to give his body enough calories. He never feels hungry, and never feels full.

"I guess you don't feel like you're eating," I ask him. "But do you feel like you're even feeding yourself or is it like you're just feeding the tube?"

He hesitates then replies, "Feeding the tube. Feeding the tube. It's not feeding me."

Watching him has made me realize how not being able to use a part of your body often means you have to pay a lot more attention to it. Like if you break your arm, you really have to take care of that arm, in a way you never did before.

For my dad, its kind of like his mouth is broken, so now a lot of his daily routine revolves around it. He can't use water to brush his teeth. He has to go to the dentist more often, because bacteria could end up in his lungs. He even has to take medicine to keep his mouth from generating too much saliva which could end up in his lungs.

"You salivate every day, but you don't notice it," he tells me. "And with me, I salivate, I notice it. My relationship to my mouth is that I just assumed and took it for granted, and now it's a huge part of my life."

It Could Always Be Worse

My dad has figured out a way to have what he calls a "snack." He buys flavored ices—like the ones you'd find in a pizza shop—puts the ice in his mouth so he can taste the flavor and get that cool feeling, and then spits it out.

He has to be careful, because even that little bit of fluid going down his throat could go into his lungs and land him in the hospital. He was there for more than a month once, but it's not really those dire the medical risks that bother him.

"The hardest part is going out with friends," he laments. "I want to socialize and I have to socialize with people by being at the table and not eating or drinking while they're eating and drinking. My wife and I do not go out for meals anymore. We used to. So I guess we save money on that."

He's trying to make a joke, to look on the brighter side.

"You know, people have worse things than this," he reminds me. "They have cancer and major heart disease, right? So everyone has something."

The Doctor Has No Clothes

I ask him if the experience has changed his view of mainstream medicine.

"Oh, absolutely, it has changed it," he shoots back. "I was very naive. I grew up thinking that doctors were magicians, and they had answers to everything...and I was angry, I said what do you mean you can't figure it out? You're a doctor! I mean how can I have this condition and no one knows its cause? No one can even name it!"

While I'm still hopeful that may dad will figure this out, and we can go out to dinner for barbequed chicken someday, he's pretty much given up. And ironically, he's happier than he's been in years. Its sort of hard to imagine, because it seems like such a miserable situation he's in...but maybe losing hope is a way to free yourself, and to find happiness in what you still have.

I ask my dad how he would have felt 10 years ago, if I told him he wouldn't be able to eat or drink anything.

"Very, very angry, very angry and very sorry for myself," he says. "I don't think I would have been as mature as I am now. I mean, it's primal. It's your mouth. You're born crying."