Quote of the episode: Regina/Emma: "You have no idea what I'm capable of"
The curse requires many ingredients, and Regina (the evil queen) had thought she had them all, but one item did not suffice. She visited Rumplestiltskin; who also grows to be another one of the most complex characters on the show. He is the man who gave her the curse, she visits him to find out what she did wrong. She tells him she sacrificed the heart of her childhood steed, and he laughs at her and says "this is the curse to end all curses you thing the heart of a horse will do" and that "great power requires great sacrifice" and tells her she must sacrifice the heart of the thing she loves most. She realizes what it is and he asks her how far she is willing to go, she says as far as it takes. Everything with Rumple comes with a price, and the cost for this information was that he will have a comfortable life in this new land, and Regina would have to heed his every request so long as he says 'Please'.
As you can see in the above clip, the thing Regina loves most is her father, who has always stood by her side. She is willing to sacrifice him, to use his heart in order to achieve her revenge/happiness.
The flashback ends with Regina going to her fathers grave saying "I love you daddy" and we see on his grave that his name was Henry; and that's where young Henry got his name, by Regina honoring her father.
When I saw this, I jumped back in seat and gasped, and to this day when I see it, I get goosebumps because I cannot even imagine ever doing anything like this to achieve something I want. The grass isn't always greener on the other side, especially when you are doing something that cannot be undone.
Meanwhile in present day Storybrooke, Regina sees Emma as a threat and is trying to get her to leave town. She frames her and has her arrested. Then Emma comes back at Regina by cutting a branch off her prized apple tree. These are two very driven women who will fight to protect the thing they love, and for both of them Henry is all they have. People can be driven when they are fighting for themselves, but they are capable of so much more when they are fighting for someone or something that they care for.
The episode ends with Mr Gold (Rumpelstiltskin) walking in on Regina picking up the pieces of her tree Emma cut down. Regina asks him who Emma is, and he tells her he would think she knows exactly who Emma is. Regina pushes for the information but Mr Gold, exits by saying "I suggest you excuse me, please". It is at this point where you start to wonder if Gold knows anything of his life before the curse, and if so how much, or if that please was just a per chance request.
The Thing You Love Most is one of my favorite episodes of the series as it is a kick point for the show and introduces many things. You learn that Mary Margaret, Henry's teacher (Snow White) gave him the book, and when Emma hears this she realized 'hey wow, there is a .001% chance this woman could be my mother', but then writes it off. We learn of Gold's relationship with Regina. We learn what exactly she had to sacrifice to enact the curse, and saw what Regina was willing to sacrifice to do it. Most importantly, this episode is the start of a great rivalry between Regina and Emma.
