"I have found out that there ain't no surer way to find out whether you like people or hate them than to travel with them." — Mark Twain, Tom Sawyer Abroad.
When I was 15 and living in Sri Lanka, a ceasefire was declared and the highway to Jaffna, in the country's north, opened up. Mum was keen to show me her birthplace so we booked seats in a small van with some strangers.
The journey took about 21 hours and included waiting at many checkpoints — both the army's and the Tamil Tigers'. Along the way I cut my foot, got yelled at by a soldier for trying to sit in his chair as I bled, and to top it off, when we got to Jaffna, Mum declared we'd be vegetarian for the week-long trip because of all the temple visits.
I won't forget the day she insisted we take a dip in a "holy" pond at one temple. I had some misgivings about the stagnant green water, but obeyed. A soldier stood sentry on a nearby tower. Then I saw a dead fish float past us and a very teenage tantrum followed.
I hated every minute of this "holiday", until we visited the small village where Mum was born. It was where my grandparents and family before them had lived for generations. We had to take care walking and stick to the main paths because of the risk of landmines.
Mum's family home had no doors or windows left. A large tree grew in the middle and cows had clearly been camping in there. Decades after they'd left, some of her family's belongings remained. She recognised her sister's schoolbag, took me through the different rooms and showed me the mango tree in the backyard. She reminisced about how she and her siblings would carve their names into the fruit, claiming them even before they'd ripened.
It was a tour through her childhood, and for the first time I could actually picture my mother as a kid, learning things about her I wouldn't have otherwise.
Since then we've had many trips together. And while she doesn't force me into suspicious bodies of water anymore, there are times we still test each other's patience on the road.
'I realised just how much we have in common'
Travelling can be "an intense social pressure cooker," says travel writer Pippa Whishaw.
"What with all the navigating, room-sharing and constant decision-making. The thing with travelling with family is you often feel so comfortable you don't bother to control or hide your irritation."
Pippa's relationship with her dad Michael had always been great, but she says it changed when they took a road trip through Spain and Portugal, a year after her mum died.
"It was a pivotal, special experience, giving us time to grieve and talk, and to make our own memories in a new reality where there was just the two of us," she says.
They got to know each other better as adults — as friends.
"I realised just how much we have in common — high energy levels, a big love of food and wine — and while he was still my dad, being removed from the familiar context of home meant I learnt more about him as a person; his history and stories and interests.
"I witnessed in him an amazing openness, curiosity, adventurousness and sense of fun that I'd never quite appreciated. In many ways he seemed younger to me."
They even had late nights out.
"Dad was often up for it, and I sometimes think his drinking stamina was better than mine!"
Of course they had their moments, when "his daddish tendencies" got on her nerves, but they have since made a yearly tradition out of their joint trips, going to Italy, Morocco and the US so far.
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'By the end of the trip we were best friends'
In the mid-'90s, 19-year-old Desi Leary and her older brother Steve travelled around Europe for 10 months. They started in Greece, where their parents are from.
She says they "got along okay" before the trip, though she didn't know him that well.
"The six-year age gap made things tricky," she says.
"When I started high school, he was starting his working life. I was the annoying sister and he was the distant brother who crossed paths with me to use the bathroom.
"I used to think he was a dick," she confesses.
By the end of the trip, they were best friends.
On their return, Desi even began defending Steve's tattoos and dreadlocks to their parents, who weren't happy that she took his side.
Travelling with a big brother was great, she says, because he was protective but not strict.
Their relationship was tested at times, though.
"I love shopping — lots of shoes for me and not so many for my brother. He was a bore to shop with, but he tolerated it!"
"It was also not great when he noticed a girl and brought her back … the walls were very thin!"
'I wouldn't do it again'
And then, sometimes, your patience is tested a little more.
Earlier this year, Harry and his brother travelled around South America for five weeks. It was their first trip together by themselves.
Harry (who preferred not to give his full name) wouldn't do it again. At least, he says, not for a long period of time, and definitely not in the same room.
"I realised on this trip that we have grown apart and lead very different lives. We have totally different travel styles and that ended up being the cause of a majority of our problems."
They did have some good times and his brother's knowledge of Spanish and planning skills helped.
"He'd made an Excel spreadsheet of everything to do on each day … That was useful, but also caused a lot of problems," says Harry.
"I don't enjoy planning and prefer to go with the flow … I enjoy hitchhiking, couch-surfing, cheap hostels, street food. My brother prefers comfort, nice hotels and good restaurants."
Of course, he knew this before the trip and says he tried to compromise.
"But it wasn't long before my frustrations at him came out. Being together 24/7 in shared hotel rooms did not help things. We ended up separating a few times, but that didn't last long."
He says it's a little sad because he'd hoped the trip would be a good way to bond.
"But it had the opposite effect, really."
He feels things might have been better if they'd been open about their disagreements, instead of bottling them up to the point of frustration.
Harry's advice for others considering travelling with a sibling?
"I want to say 'don't'. But I guess everyone's different."
He says if you're able to talk about it and communicate your issues, go for it.
"Also, don't stick together 24/7 for five weeks like we did. You need time alone and to understand that the other person needs it, too."