By Jon Kay
BBC News, Ypres
The journey to Ypres has been emotional for all three
How much do today's teenagers know about World War I?
One man took his two grandsons on a personal journey to the Western Front, for a history lesson they are unlikely to forget.
Before coming here from their home in Somerset, James White and his younger brother Simon weren't sure when the Great War happened.
They didn't know what the Armistice was about - and they didn't understand why we wear poppies.
Now, their bright white trainers are caked in mud as they step gingerly through the trenches at a military museum near the Belgian city of Ypres.
"Ugh. It's disgusting," squeals James, 17, as the chocolate-brown soup seeps through the soles of his shoes.
"My feet are freezing. I don't know how those soldiers put up with it. I couldn't."
Robin, the boys' grandfather, laughs as he watches the teenage pair struggling in the mud.
Robin and his grandsons in Ypres
"That's nothing!" he teases. "The lads who fought here would have been cold and wet for weeks on end.
"They'd have had rats nibbling at their toes. You boys don't know how lucky you are!"
This is why Robin has brought the boys here - to see the reality of the trenches.
"Kids today just don't understand the First World War," says Robin. "They learn about the Second War, but the 1914 conflict just gets ignored.
"If we're not careful, the younger generation of today will never know what happened."
He's right. James and Simon don't have much understanding of World War I.
"We didn't really do much on it at school," says James, who wants to become a police officer.
"And the stuff we did learn was just from text books. You learn so much more from real, hands-on experience."
The brothers were touched by by what they found out about George Thatcher
Robin, 65, wants to show James and Simon the scale of the loss in the war, so we head to the Menin Gate Memorial in the centre of Ypres.
It is a vast monument containing the names of 54,896 Commonwealth soldiers who died without graves. Every name is carved into the giant stones.
The boys are clearly overwhelmed by the sheer number of names.
"I'm amazed," says 14 year old Simon. "It's devastating to think how many there are."
His older brother is also standing there, open-mouthed. "I've never seen anything like this before," he gasps, "I can't even find a word to describe it. It's hard to believe."
Robin Wright has a very personal reason for bringing them to the Western Front.
His own grandfather - the boys' great-great-grandfather, George Thatcher, died here on November 2nd 1918, serving with the 1st Battalion, Bedfordshire Regiment.
He died just a few days before the end of hostilities. Robin has researched what happened to George, and now he wants the boys to understand.
So, in torrential rain, we drive south across the French border. From the regimental war diaries, we've been able to pin-point the exact location where George was gassed in the trenches.
It is now a potato field on the outskirts of Beaurain village, near Cambrai.
Like a military general himself, Robin leads his grandsons through the mud, right into the middle of the field.
He points towards a church on a distant hill. "That's where George and his mates were heading on the night he was gassed," he tells them.
"The gas was a terrible way to die. You couldn't see it coming. You didn't know it was in your lungs until it was too late."
The boys' great-great-grandfather died just before the end of the war
"The shells were falling all around. The horses would have been in a mad panic. You can't take it all in, can you?
"Would you have liked to have swapped places with him?" he asks his grandsons.
The brothers look at one another and shake their heads.
After he was gassed, George Thatcher was taken to a hospital near Calais, where he died of his injuries. The boys' final stop is the cemetery where their great-great-grandfather is buried.
Robin, James and Simon process into the graveyard. They walk along the lines of white head-stones, looking for George's final resting place.
Just two days ago, the young brothers didn't even know George's name. Today they shout "Here he is!" as they spot 'George J. Thatcher' inscribed on his simple grave.
Heads-bowed, the trio lay a wreath of poppies - and stand in silence.
"It's amazing that, in two days, you can find out so much about someone," says James.
"I'm going to tell my mates that we should be more thankful," adds Simon as he looks at all the graves around him.
"These men made our lives better - but they gave their own lives."
James agrees: "I'm definitely going to remember this."
"These guys were heroes. We should respect them and what they did."
Robin has tears in his eyes as he listens to his grandsons.
It has been quite a journey.