I think that I am a relatively unemotional writer. I find it difficult to express certain feelings in words. I'll add the line in and delete it within a second. I do so much better with unspoken feelings; actions and glances. I even recently retroactively edited a story - something I usually never do - to delete a line I hated because I thought it was too emotional for the moment (admittedly, it was also just a really crap line.)
I'm trying to improve on letting characters say and feel stuff, considering that this is one of the generally accepted reasons for fan fiction - we write what the official canon can't. But it's difficult, when these are characters who just don't have that kind of pull - when the phrase "thank you" holds the most emotional impact from the canon to date. You have to work to make it plausible. And that's it for me, I think. I want everything I write to conceivably fit into the show in some way (yes! even when it involves raving psycho killing!) I'm afraid to take that step to the left. When I have, I've usually been unhappy with the result.
And I feel like I need to learn how to do this emotional communication thing with original fiction. Or I'm not going to be very successful in creating the sorts of narratives I want to. I might end up with a bunch of stories which are potentially technically good, but devoid of resonance.
I think about this type of thing way too much.