WRITINGWELL: I think Castle’s biggest insecurity is that he’s not enough - not man enough, not fun enough, not cool enough, not good enough under pressure, not strong enough…thus his dramatic persona and his over-the-top gestures and his acting something like an ass. It’s all to make up for this feeling that he’s never going to amount to every expectation. I find evidence for this in his mother’s career being curtailed or altered due to his existence and their interesting relationship now. Also, the paper he didn’t write but which he got credit for and how that apparently haunts him. He’s afraid that Kate will see he’s not enough. Not what she needs, not able to be for her what will make her stronger. Remember the episode with Dick Coonan taking him hostage? He brings Kate dinner from like five different places in an attempt to make up for what he lacked so spectacularly in that moment. And she knows immediately what he’s doing - sees right through him - and she says, It’s not your fault.
As for Kate, her biggest insecurity looks to be the same. I don’t know, really. Harder to pinpoint with Kate, but her father’s drinking told her - you’re not enough to keep me here. Her mother’s unresolved case has told her - you haven’t done enough. Evidence for that during the Rathborne thing when she tells Castle she doesn’t want to let her mom down. Castle’s incident with the weather girl at the beginning of this season said to her, apparently, you’re not enough to keep me here. (Among other things, I guess, but jeez, Kate, really?)
So, yeah, maybe their insecurities are the same. And maybe to combat them, they’ve become a little overblown and extreme in their responses. So Castle is the playboy jackass and Kate is the obsessive neurotic. They became, in essence, *too much* in order to compensate for not being enough. And so then THAT too becomes an insecurity, right? Being too much to handle.
Just thinking out loud. Good question.