Why does Jack propose to Lucy so fast?

All the timing is, of course, artistic license. But spending time with each other doesn't have to be a date, per se. I think Jack fell in love with Lucy when they were walking back from his penned-in truck to her apartment. Talking and laughing together is way better than going on some stiff dinner date!

Would it have been as romantic of an ending if Jack had merely asked her on a date?

I'm watching it on TV right now, and while it is ironic that Jack proposes to Lucy after having known her for a week as opposed to the three months she was 'supposedly' with Peter....I think a lot of it is Jack and Lucy had a lot of quality time together and honest conversations about what kind of people they were, like when they talk about her dad, and Lucy reveals that her coat was her father's, and the dreams she and her dad shared. He got to know what Lucy held dear and important, deep down, and it matched what he holds dear, deep down. And Lucy realized this too (the next day she does her "I'm having an affair!" bit.)

It probably helped them both, in a bizarre way, that neither of them was looking to fall in love. Jack thought of Lucy as his future sister-in-law, Lucy was still 'in love' with Peter (or at least the image she had created of him in her mind). Jack and Lucy, to me, come across as being a little on the shy and guarded side, not having the pressure of a potential romantic pairing probably made it easier for both of them to be more open and honest with each other. It was after being open and honest with each other that they realized how much potential there was between the two of them.

And actually, you *really* see how well they've gotten to know each other in their 'fight' scene, where they both call the other one out on what they're doing with their lives. They each hit the other's sensitive spots dead-on, which would indicate in the short time they knew each other, they *really* developed a strong understanding of the other.

Lucy's confession at the end was also telling and touching as well...that she was lonely and with the pretence, she had gained a family that she now loved dearly, and loved her. You could see it in their faces...that while they were shocked, they were also very sad for her. I often suspect that if Ashley and her husband hadn't shown up and created a scene, Lucy might've found herself in the middle of a huge group hug.

So, yeah, a week is quick....but the movie did a pretty good job of showing Jack and Lucy's 'true selves' to each other, so what else were they going to find out by dating each other? :)

Because it was love at first sight for him - when he first meets Lucy at his parents house, the look on his face when she leaves says it all.

And we know Lucy believe in love at first sight too because she tells Peter so when he's in the coma.

Plus, yeah, it's a rom-com, so real time doesn't apply!

Lyndon Johnson proposed to Lady Bird the morning after he met her.

Jack Paar proposed to his wife no later than two days after they met.

Dick Francis, the British jockey turned mystery novelist, said that when he first met his wife, he told himself that she was the woman he was going to marry.

My husband (unlike LBJ, Paar and Francis, no one you ever heard of) said he wanted to propose right after our first date, but he was afraid such a quick proposal would scare me off. So he waited--a whole six weeks.

Psychologists have said that men form a mental picture of their ideal woman, so when they meet someone who fits that image, she's The One. To judge by the divorce rate, it would seem that this feeling isn't reliable and some men see what they want to see and not the real woman. And yet the Johnsons, the Paars, the Francises, and my husband and I married in haste and have NOT repented at leisure.

I still wouldn't recommend such haste to anyone else now that we know that insistence on a quick commitment is one of the classic signs of an abusive man.

i think ur trying to grasp hollywood formulaic romantic comedy logic

LOL

I guess maybe they felt they knew, I'm just skeptical because my sister got engaged to someone really fast (10 days of knowing each other) She thought she "knew" and it ended being a really bad situation. So now I think even if you think know, it still doesn't hurt to take your time in getting to know each other. But oh well, just a movie.

He had to propose to her right away, because the movie was almost over!

I intend to live forever.
So far, so good.