Thinking so hard about that, "Prove it," in the park scene and why Daniel reacts so strongly to Armand's fucked up little love confession.
Daniel Molloy has driven away everyone who ever loved him, and he knows it.
By the time we see him in S1, he's been divorced twice, he's estranged from his children, and he has no friends to speak of. All he has is his career, which he holds onto as the one thing he did right in his life. He even tells Louis: I was bad at everything else, but I was a good journalist. He has accepted this about himself. He knows he was the problem in all his relationships - the choices he made and the hurt he caused are the reason he's alone. That is a HEAVY pill to swallow, especially when you're in your 70s and staring down the barrel of a terminal illness.
Then suddenly, he's a vampire. He's not dying anymore. Now he's going to live forever. What's he gonna do with all that time? The only thing he knows how to do is be a journalist, so that's what he does. He throws himself into making his documentary because it's literally all he has. He's not like Louis, whose mortal family still loved him and wanted him around even after he turned, or Lestat, who quickly made fledglings of the people he loved so they could spend eternity with him.
Daniel tells Louis: "Vampire loneliness - I get it now."
Daniel doesn't have people who love him. He ruined all that. All he's got is his career as a journalist. So that's what he spends his eternity on - he's gonna make his documentary and wring some truth out of Lestat, because it's a distraction from facing down eternity as an immortal who is not just alone, but who has lived a long life and come out if it with the conclusion that they are fundamentally unlovable and its their own damn fault.
And now here's his maker again. Fuck this guy, right? Armand is the one who gave him this immortality, which he's now going to have to spend alone and unloved. And to top it all off, Armand left Daniel too. At least this one time, Daniel can say that it wasn't his fault, and he can pour all his anger and frustration out on the one person who left him when he didn't deserve it.
And then Armand says, "By the way, I love you."
"I've been here the whole time. You thought you pushed everyone away? You didn't. I'm here. I've always been here."
"Do you remember all the times you were a bad husband? I was there and I still love you."
"Do you remember all the times you were a bad father? I know about that. I still love you."
"Those awful, shitty things you've done? I know about those too and I'm fine with them. You aren't repulsive to me. I still love you."
"I've cared for you at your worst, and I still love you."
"I know you need your career to give your life meaning. I'll even support you in that if you let me. Because I love you."
"You're tattered, and you're broken, but I still want you to be mine."
