Rose, You're No Picnic. You're A Spoiled Little Brat, Even
The romance between Jack and Rose is unforgettable and intense because it is partly raw. Unlike the rest of the Titanic, which is embellished and superficial, Jack perceives the true Rose that others ignore. Jack is trying to convince Rose not to jump off the ship and end her life. He tells her that she is not a picnic, meaning that she is not easy or pleasant to deal with. He also calls her a spoiled little brat, meaning that she is selfish and immature. He says that she is even, implying that there is something worse about her that he does not want to say.
Jack is using a casual tone to express his frustration and anger with Rose, but also to show that he cares about her and wants to help her. As a poor man, he regards the wealthy as spoiled, and he is not mistaken about Rose. Yet, in spite of his opinion, he still loves her, and she still loves him even after he tells her. Although fans anticipated that Rose and Jack's romance was destined to fail, it did not prevent them from hoping for their happiness.