Tashi Wheeler's life has been one big trip. She has visited 60 countries and made eight treks through Nepal. But the 22-year-old student hasn't squeezed her exotic journeys into an extended gap year; she began travelling the world not with a rucksack, but in one, when she made her first trip to Kathmandu as a tiny baby on her mother's back.

Tashi is the daughter of Tony and Maureen Wheeler, the founders of Lonely Planet guides. Lonely Planet is 30 years old today, and alongside the success of these backpackers' bibles has grown the first generation of children who have been taken away on worldwide adventures.

Like many parents, I have followed in the Wheelers' peripatetic wake. I've clocked up the air miles with my own three children - a 10-year-old and two-and-a-half-year-old twins. They have camped in the Damaraland desert, bedded down in a tree house in Costa Rica, and called countless coastal villas home for a fortnight. But recently, when I was planning yet another family trip - to the north-east coast of Brazil - I began to have doubts. They needed lots of nasty injections, which made them horribly ill. Dengue fever - against which there is no protection - was rife in Rio, where we would be stopping for a few days. The flight was 12 hours, and the twins had just started potty training. A well-meaning friend gently suggested: "Perhaps they'd be happier taking their buckets and spades to Bognor. It's you - not them - who wants to go to Brazil."

My friend is right; although parents presume that an itinerant childhood is an enviable learning experience, we don't bother to consult the children themselves. But now the first generation is adult, we can ask them: is far-flung travel as a child good for you when you grow up?

One argument for being a vagabond babe seems unassailable: the lucky child (it's still only relatively privileged families who can afford such adventures) will be reared with a deeper understanding of distant people. But Wheeler - Tashi is Tibetan for blessing - admits she has dabbled, rather than delved, into different cultures, never staying in one spot for more than a few nights. Rather than knowledge of any particular place or people, it's the art of travelling itself at which she excels. "I was 13, maybe 14. Can't quite remember. It was in Bali, or perhaps it wasn't, but that's where I remember it was... " is how she typically starts a sentence, waving her arms around. She can barter with the best of them, and erect a tent in minutes. But even today, she speaks no languages other than English.

Wheeler relies on photographs to reconstruct her rambling life, as if her memory is a box of jumbled snaps that she has yet to sort out. "I remember playing with a boy on a beach; a bus ride; having a baby elephant step on my foot. But I just can't remember where," she says.

A few incidents, however, she recalls with such sharpness that they provide a skeleton on which to hang her childhood. "I first went trekking in Nepal when I was five. Halfway up the mountain, the sherpas stopped and bought two chickens. Kieran (her brother, two years her junior) and I were playing with them, singing to them, as we went up the path. I remember this so clearly because when we stopped to camp, they chopped the chickens' heads off. We'd named these chickens. Then they were killed."

The opportunity to share such stories are few. Helen de Jode, 37, was taken on long holidays up to the age of 10, and remembers the feeling it gave her of being set apart. "We attracted quite a lot of attention everywhere we went. People were very interested; I liked it. I suppose I was a bit of a princess. Then you come back home, and you're absolutely nothing. People aren't even interested in where you've been."

I know my own 10-year-old censors her "What I did in the holidays" start-of-term essays, for fear that her classmates will think her odd, or even a liar. Wheeler is still reluctant to tell of her extraordinary journeys. "I don't bring it up in everyday conversation, because I feel I'm boasting," she says.

Unable to confide in others, Wheeler grew even closer to her family. "It's given me and my brother a very special relationship. When we sit down and talk, we have a special conversation, because we've been through something different. We talk about things that none of our friends talk about. It's something that we share."

Aged five, Maya Catsanis's mother took her and her two-year-old sister on a year-long, round-the-world journey. Perhaps because this was the only time she went abroad with her family, Catsanis has more solid recollections than Wheeler. And, because she was so young, nearly all these memories are very sensual. "I remember eating fruit salad with salt on it in Singapore, and thinking how strange that was. I remember having my sixth birthday in Bali, and the batik outfit mum bought me and the chocolate cake in the shape of a monkey we had in a cafe."

Although nomadic mothers may treat their kids, the success of the journey comes before any childish desires. "I had a ginormous baby doll called Charlotte," says Wheeler. "Mum always made a big thing that I had to leave her behind because she was so big, and gave me a little teddy bear to pack instead. So I used to hide her, under my coat or something, and smuggle her along."

Catsanis, now 30, a dedicated traveller and Lonely Planet's London press officer, insists: "Mum thought it would benefit us, she had our interests at heart. But it was primarily her ambition. She had worked every weekend for two years as a waitress to save up money for the trip."

To keep travelling, her mother had to trade along the way. "Mum bought lots of string cotton bikinis in Bali, to sell when we reached the States. She had these three wicker baskets with our clothes on top and the bikinis at the bottom, hidden underneath, because she didn't want to pay any import tax. So she used my sister as a distraction, pinching her to make her cry and scream so the customs officers would just wave us through."

Wheeler believes the constant departures become more awkward as you get older. "I was a kind of socially retarded teenager," she says, trying to make a joke of it, "because I didn't know how to react to other kids. I hadn't hung about with them during the holidays, I didn't know social norms and the whole boy-girl thing. You wouldn't go to Malaysia, where I spent my holidays, and be flirting with guys, as it just wasn't on. So I didn't know how to do it when everyone else in my class did."

Would Wheeler have preferred a more sedentary childhood? It's a question she simply can't answer. "It was just normal, it was just what we did. Whether I wanted to go or not didn't matter; I had to."

For De Jode, who has spent most of her adult working life in Africa, the rewards are more tangible. "It gave me the confidence to travel quite freely, and think travel itself was a good thing. I resent my parents for plenty of other things, but never for the fact that we were dragged off."

I took my family away again last weekend. When we were out walking, we met a man who stooped down and asked my globetrotting toddler where she lived. I looked on, wondering if a two-and-a-half-year-old would be able to answer, "London". It took her a moment, but then she knew: "I live on an aeroplane."

What have I condemned my children to? Rootlessness? An inability to call any one place home? I consult Wheeler: could she ever settle down? "Not permanently, no. I could never sit in one place and be happy. I don't want to have to settle anywhere."

But she is a success, a daughter to be proud of. This week, she starts her MA in Oxford, a city, she tells me with some satisfaction, she's never been to before. Then, a moment later, adds: "At least, I don't think I have."