I happened once to catch an episode of "Sex and the City," where a character bemoaned that the hard part of writing was being able to hold a thought in your head long enough to write it down.
I totally understand what [this fictional person] was saying. It's an apt insight into what the ability to write really is about. It's not just about coming up with interesting thoughts but also being able to capture them on the page.
Unfortunately I find my ability to write wavers from time to time. Sometimes it's because I can't come up with anything interesting to say (although this isn't often the situation…), but lots of times, like now, it's because my mind is too… cluttered? busy? distracted? to be able to hold onto my thoughts long enough to get them down. It's like having overloaded RAM - there's just no space to hold thoughts while I process them. Either I need to start deleting stuff or get a bigger swap file…
It's all very frustrating. I usually sense that there's a perfect way to articulate what I want to say, but I just can't conjure it up when I go to try. It ends up leaving me feeling trapped in my own head. If I really work at it I can sometimes eek something out, but I hate not being to capture my ideas perfectly. And sometimes an imperfect expressions just won't do. If I can't explain myself with precision and delicacy, I'm better off not even trying. (Thus I'm getting increasingly behind in all the things I want/need to write yet can't write quite right right now…)