I think they probably had a very strong infatuation with each other, and had they both survived, they WOULD have developed into a long lasting love... but, with what happened in the movie surrounding their "love story" I don't think it was real love.
a. Jack would NEVER have been allowed in first class
b. having sex with someone that fast was NOT NOT NOT accepted socially back then. (actually, most things they did wasn't proper back then)

Yea, real love like that probably does exist NOW....back then, I don't think it did. People didn't marry for love back then, they married for social relief and finanacial relief. The didn't have the "dating" thing.....and they most certianly did not have sex before marriage. In fact, they didn't show any sign of public affection at all. It wasn't tolerated in her class, and she would have been looked badly on, and her mother would have been ashamed of her.
So, if nothing in this "love story" would have happened in real life in 1912, you can't convince me that it was real love.
Now, I know people are going to say that it does, but I think after seeing the movie you are just getting swept up in it.... and I think if you continue to think that way, when you DO fall in love with someone, you will be sadly disappointed.
People just don't act the way they did in the film for more then 3 months....
I've been with my husband for 5 years now, and we have stopped trying to impress each other with our chivalry..... afterall, chivalry IS dead.... now we're being realistic and practical.

Rose and Jack were a typical Hollywood love story, not a realisitic one.