In common with many people around the world, I've been fascinated with the Titanic story ever since I first heard about it as a young boy growing up in southern England.
 
I've always felt a tiny bit invested in the saga too because my grandfather was a merchant seamen based in Titanic's home port, Southampton, and occasionally we'd visit him at the docks.  I can still picture the big liners, the giant ropes tethering them and the huge cranes filling their holds.
 
Then, as a young man, I had several friends who worked at BBC Radio Solent, the area's main local radio station, in whose building, South Western House, Titanic's passengers spent their last night before setting sail.  It was said the main studio was haunted by the spirit of one of those on board. 
 
A distant view of the building is visible in the opening moments of the famous movie.
 
So, I was pleased to be asked to file a story for Al Jazeera English from the National Geographic exhibition in Washington DC titled, "Titanic: 100 Year Obsession."
 
When you walk in your eye goes straight to a scale model of the ship, as she was in 1912, built to the same blueprints that Harland and Wolff of Belfast used to put the real thing together.
 
Further round the exhibit and you come across a scale model of the ship as she is today, three kilometres down on the Atlantic seabed, it takes your breath away.
 
Richard McWalters, from National Geographic told me why he thinks this story is as compelling today as it was one hundred years ago.
"If you imagine Boeing corporation for example bringing out their latest airplane, the largest airplane they ever made and onboard was Bill Gates, George Clooney people like that ... and for this tragedy to then happen on top of that and these people perished ... it really struck a chord."

There are monuments and statues in honour of Titanic all over the world in memory of the fifteen hundred souls who perished on the ship's maiden voyage. 

I went to one in Washington DC that offers another clue as to why we remember this ship, even though there have been worse shipwrecks since Titanic went under. It was erected in honour of, "the young, the old, the rich, the poor, the ignorant and the learned," in other words all members of society who died that day. 

The point is, Titanic's crew and passengers had to face agonising decisions. 
Who got a seat in one of the all too few lifeboats? Women and children certainly - but which men? Once in a lifeboat, should they come back to pick-up those in the water and risk being overwhelmed? McWalters put it this way.

"This is very much like a Shakespearian story ... a bit of the moral play going on so people could show their true colours so to speak and how they would respond in a situation like that."
 
Thanks to Leonardo DiCaprio and Kate Winslet, stars of James Cameron's movie Titanic, which has just been released in 3D, the story is reaching younger audiences all the time.
 
I went to a local cinema in Georgetown where I found a large group of teenage girls who were carrying Titanic posters and who were clearly in love with Leonardo - Jack Dawson in the story. I asked them what do you love about the movie?
 
Leonardo, of course, but beyond that it was that they liked, "the intensity and the fear".  
 
They were aged about fifteen years old and as such are living proof that the Titanic's story is likely to endure another one hundred years - they'll tell their children and their kids will pass it onto their own - and so by watching the popular movie they're helping to keep alive the memory of that terrible tragedy one hundred years ago.