TVD speculation
Okay, so I've been thinking. 4x08 makes no sense.
We meet Charlotte who's a puppet in Damon's hands. Literally. She went on for 70 years, counting bricks in New Orleans. She killed a guy who touched Damon's drink. She puts "creepy" on a completely new level. And she has absolutely no negative feelings for Damon, even though he abandoned her for said 70 years. She's incapable of being angry at him.
Now, we have Elena:
1. Her first act as a freshly turned vampire is to jump at Damon, fangs out, screaming: "Leave him alone!". Then she proceeds to have an argument with him about Matt. She's clearly mad at him.
2. In 4x02, before they share blood, Damon directly tells her to pick someone at the Grill and drain them ("Pick your meal"). It's a joke, yes. So is his flashback line about not letting anyone touch his drink, and yet Charlotte takes it seriously. After a direct command, Elena still says "no human blood".
3. Damon does indeed say "you need fresh blood, from the vein" to Elena... AFTER she vomits the animal blood. He says it when they're already in the bathroom, pointing at his own wounded hand, and then tells her to drink. Elena still asks questions about it before she does it, and she can't keep it down later on. Damon also says "she needs human blood, from the vein" right before Elena and Stefan go hunting for the first time. Only he says it to STEFAN only, Elena isn't even in the room yet. After Elena comes in, Damon only makes a general statement "vampires eat people." So there's no way the sire bond could've affected Elena's feeding issues, because the only direct statement that could be taken as a command ("she needs human blood, from the vein"), Elena doesn't hear, and the statement she does hear ("you need fresh blood, from the vein"), works for both human and vampire blood, so she should've been able to keep Damon's blood down. Elena's projectile vomiting in 4x02 has nothing to do with Damon's opinion, so the blood bag experiment from 4x08 is invalid.
4. Elena: Then I need to get in there.
Damon: No, Elena, this guy is dangerous!
Elena: So am I, Damon!
Damon: Then you need to be smart.
TVD 4x05, The Killer
Damon straightforwardly yells "No" and Elena yells back at him and ends up killing Connor. In 4x05 Damon forbids her going after Connor several times, tells her that she can't let him know she's a vampire, that she should stay put etc. Compare it to the s3 situation in which Klaus told Tyler to bite Caroline: Tyler said no, Klaus smiled and waved him off, the sire bond made Tyler bite Caroline anyway. So it also should've made Elena not be able to kill Connor. It should've even made Elena not be able to BITE Connor, because Damon said that Elena can't let Connor know that she's a vampire.
5. In 4x06, when they're on the bridge, Damon says "Let's go talk about this before you do something stupid" and Elena doesn't move a muscle, still determined to kill herself. This is probably the weakest example here, because you could argue that the hunter curse overrides the sire bond, but if there were indeed two opposite supernatural forces controlling her, shouldn't there be at least SOME sign of conflict?
Those are just from the top of my (very sleepy) head. I'll try to think of more.
To sum up: either s4 has inconsistencies and plot holes that a 5yo could eliminate, or the sire bond doesn't exist. The theory is built by Stefan and Caroline (who have no knowledge of any of the examples listed above), and then Damon and Elena start believing it too: him, because he's insecure like fuck and doesn't believe that he could get something good; her, because she has very little knowledge of sire bonds in general.
We meet Charlotte who's a puppet in Damon's hands. Literally. She went on for 70 years, counting bricks in New Orleans. She killed a guy who touched Damon's drink. She puts "creepy" on a completely new level. And she has absolutely no negative feelings for Damon, even though he abandoned her for said 70 years. She's incapable of being angry at him.
Now, we have Elena:
1. Her first act as a freshly turned vampire is to jump at Damon, fangs out, screaming: "Leave him alone!". Then she proceeds to have an argument with him about Matt. She's clearly mad at him.
2. In 4x02, before they share blood, Damon directly tells her to pick someone at the Grill and drain them ("Pick your meal"). It's a joke, yes. So is his flashback line about not letting anyone touch his drink, and yet Charlotte takes it seriously. After a direct command, Elena still says "no human blood".
3. Damon does indeed say "you need fresh blood, from the vein" to Elena... AFTER she vomits the animal blood. He says it when they're already in the bathroom, pointing at his own wounded hand, and then tells her to drink. Elena still asks questions about it before she does it, and she can't keep it down later on. Damon also says "she needs human blood, from the vein" right before Elena and Stefan go hunting for the first time. Only he says it to STEFAN only, Elena isn't even in the room yet. After Elena comes in, Damon only makes a general statement "vampires eat people." So there's no way the sire bond could've affected Elena's feeding issues, because the only direct statement that could be taken as a command ("she needs human blood, from the vein"), Elena doesn't hear, and the statement she does hear ("you need fresh blood, from the vein"), works for both human and vampire blood, so she should've been able to keep Damon's blood down. Elena's projectile vomiting in 4x02 has nothing to do with Damon's opinion, so the blood bag experiment from 4x08 is invalid.
4. Elena: Then I need to get in there.
Damon: No, Elena, this guy is dangerous!
Elena: So am I, Damon!
Damon: Then you need to be smart.
TVD 4x05, The Killer
Damon straightforwardly yells "No" and Elena yells back at him and ends up killing Connor. In 4x05 Damon forbids her going after Connor several times, tells her that she can't let him know she's a vampire, that she should stay put etc. Compare it to the s3 situation in which Klaus told Tyler to bite Caroline: Tyler said no, Klaus smiled and waved him off, the sire bond made Tyler bite Caroline anyway. So it also should've made Elena not be able to kill Connor. It should've even made Elena not be able to BITE Connor, because Damon said that Elena can't let Connor know that she's a vampire.
5. In 4x06, when they're on the bridge, Damon says "Let's go talk about this before you do something stupid" and Elena doesn't move a muscle, still determined to kill herself. This is probably the weakest example here, because you could argue that the hunter curse overrides the sire bond, but if there were indeed two opposite supernatural forces controlling her, shouldn't there be at least SOME sign of conflict?
Those are just from the top of my (very sleepy) head. I'll try to think of more.
To sum up: either s4 has inconsistencies and plot holes that a 5yo could eliminate, or the sire bond doesn't exist. The theory is built by Stefan and Caroline (who have no knowledge of any of the examples listed above), and then Damon and Elena start believing it too: him, because he's insecure like fuck and doesn't believe that he could get something good; her, because she has very little knowledge of sire bonds in general.