Bob Newhart's comedy ages well. Watch his sitcom from the '70s—the one that cast him as Chicago psychologist Dr. Bob Hartley—and you'll find the only part of the show that fails the test of time is the wardrobe. Wide lapels and tacky ties aside, the jokes and Newhart's willingness to be the butt of them are as funny as ever. The same low-key manner and signature stutter that made him a staple of weekly television for more than two decades also earned him three Grammy Awards for his comedy albums, roles in a dozen Hollywood films, and steady bookings on the nightclub circuit.

These days Newhart insists he's too old for another TV series, but he might be up for a sequel to the 2003 holiday film Elf that had him playing opposite Will Ferrell. He also occasionally takes his stand-up shtick on the road just to make sure that he hasn't lost his edge. He hasn't. When the Post visited with him recently, he was catching his breath between a booking on the East Coast and a trip to San Francisco where he was to perform before a sold-out convention of, believe it or not, psychologists.

Did we mention that he's 78?

Last year Newhart added "author" to his long list of credits, although he admits that he's embarrassed when his publisher, Hyperion, touts his slim, 256-page book as a "memoir." Out this month in paperback, I Shouldn't Even Be Doing This isn't exactly an autobiography, and it's definitely not a celebrity tell-all. He shares great stories but never dishes the dirt. He puts himself down more often than he pumps himself up, and he randomly drops in whole paragraphs from some of his most memorable monologues. Half serious and half silly, it's vintage Newhart.

Post: Your book is probably driving the clerks at Barnes and Noble crazy. It doesn't belong on the shelf with the autobiographies, and it doesn't quite fit into the humor section. How would you describe it?

Bob: Well, I'm not sure. My publisher calls it a "memoir," but I think that's a little highfalutin for what it is. Memoirs are written by the Marquis de Sade or geishas. Actually, one of my motivations for writing the book was to pass along to other comics a few ideas and thoughts that might save them some heartache along the way. I wanted to say, "Here's how I handled things." For example, the first five years of doing stand-up comedy were abject terror, as far as I was concerned. So, if you're a comedian and you feel that way, don't worry, everybody feels that way…but you can't let on.

Post: Speaking of being terrified, in your early days of doing stand-up comedy, you got so nervous that you'd start pacing an hour before the show….

Bob: I still do. I would miss it [the terror] if I didn't feel it. It's like a friend in the room. He arrives about two hours before a show, and I'd feel naked walking out onto the stage without him. When you're a stand-up comedian, you're basically saying to an audience, "I'm going to make you laugh for an hour and 15 minutes." That's a rather conceited thing to say, but that's the underlying statement that you're making. Every booking is a new challenge, and each audience is different. Just because the last show went well doesn't mean the next one will go equally well. You can never become complacent.

Post: Let's talk about your early days. You graduated from college, did a couple of years of military service, and were on a traditional track that would lead to a career in accounting and a house in the suburbs. How did your parents react when you announced that you were going to be a comedian instead?

Bob: They thought I was crazy. I left accounting because I realized I wasn't cut out for it. I decided to take a year off and try to do comedy. One year became two; two years became three. At one point all my friends were buying cars and getting married, and I was living at home and working at a Chicago department store during the Christmas season. I remember thinking, Man, you have really screwed up your life! But then something would come on the horizon and I would say, "OK, if this doesn't pan out, I'll drop the whole idea." Then something else would come on the horizon, and I'd say, "OK, if THIS doesn't pan out…," which was my way of saying, "This is really what I want to do." I kept coming up with reasons not to give up. I didn't want to go back into accounting and spend the rest of my life saying, "I wonder what would have happened if I had stuck it out for another six months." Then the record album [The Button-Down Mind of Bob Newhart] came along, and I was off to the races. People were asking, "How many Ed Sullivan shows do you want to do?" "Can you come out to L.A. for the Emmy show?"

Post: Your style of humor was so different from what was popular at the time. Did you realize that you were creating a whole new kind of comedy?

Bob: [laughs] I'd like to take credit for it, but there were a lot of people who preceded me—Mort Sahl, Shelley Berman, Lenny Bruce, Jonathan Winters, to name a few. We didn't all get together and say, "OK, let's change the face of comedy." It was just our way of expressing our view of life and the strange planet we all inhabit. We were dealing in areas that hadn't been dealt with before.

Post: A lot of fans remember you best as Dr. Hartley, even though the show went off the air in 1978. You say in your book that you and Bob Hartley are about 85 percent the same. How are you different?

Bob: The other 15 percent is my dark side. I tend to find humor in the macabre. It's my way of dealing with the injustice and insanity of the world. My wife sometimes says to me, "You know, if the public ever found out what you're really like, they wouldn't show up for your performances." I say, "But we aren't going to tell them, are we?" She agrees; no, we aren't going to tell them.

Post: You've been married for 44 years. A lot of your role models—Jack Benny, George Burns, Don Rickles—also have had long and successful marriages. Is this a reflection on your profession? Do comics make good husbands?

Bob: I don't know if we make good husbands, but you're right, comedians' marriages tend to last a long time. I attribute it to laughter. I think an important part of a lasting marriage is humor and the ability to laugh at ourselves. That's what has helped us get over the rough spots. Ginnie and I might argue about something, but then one of us will say something funny and I'll think, I better write that down; I might be able to use it in one of my comedy routines. We both end up laughing.

Post: You and Ginnie are good friends with Don Rickles and his wife. What's he like offstage? Does he crack one-liners nonstop, or does he have a quiet side?

Bob: He isn't "on" all the time like he is when you see him perform in a nightclub or when he's a guest on a TV talk show. I liken him to Muzak. He can be on in the background but you don't necessarily have to listen to him. People ask me, "How can you and your wife go away on vacation with Don Rickles? Doesn't he drive you crazy?" I say, "Well, he would if I paid any attention to him, but I don't. I just tune him out."

Post: You seem to be in an enviable place, career-wise. You can work as much or as little as you want. Any chance there might be an Elf II?

Bob: If New Line Cinema [film company] can ever kidnap Will Ferrell, tie him up, and put him in a safe house, there might be another Elf…but he's so busy. As for me, I'd never go back to the grind of a series, but I've got a couple of things that are hanging fire. I don't rule out a return to television, but not in a weekly format.

Post: You and Ginnie have four children and several grandchildren. Is there a budding comedian in the bunch?

Bob: They all have a wonderful sense of humor, probably because they've been living around comedy for so long. When I'm about to say something that I think is funny, my upper lip kind of curls, and they know what's coming. They say, "Oh, brother, here it comes. Dad's going to say something silly." But as far as making a career out of comedy, the kids all tried it but they didn't love it, so they wound up doing all kinds of other things. They had seen the unromantic, backstage part of the business.

Post: For example?

Bob: For example, when I play Vegas, I often have to walk through the kitchen to get to the stage. That's not exactly glamorous. These days, the hotel manager will say to me, "I'm sorry, we have to go through the kitchen." I say, "Well, I'd feel strange if we didn't go through the kitchen; I've been walking through kitchens all my life. It's like, oops, watch out for that piece of celery…you don't want to slip on that!”