my personal experience, which is that whenever I write what I think about a subject, it always turns out that my thoughts do not hold up on paper? No matter how confident I am in my thoughts, they reveal themselves on the page as little but logical holes, contradictions, and non sequiturs.
Pre-emptive note: it seems logical that the very next paragraph references Paul Graham directly; my very next move was going to be to connect the writer's self-reported experiences here with Graham on writing, had it not been the case that that job was already done.
As I've said before: I'm not in the same boat with Graham on the writing-is-thinking stance. The difficulty with seeing my own thoughts fixed in words after an initial pass is not in their inadequacy or their being a source of illusory and fleeting comfort with said illusion now made stark for everyone to see, but a mixture of (a) a lack of "punch", and/or (b) the places where a dishonest broker could exploit the yet-to-be shored up wording to suggest/assert the presence of some weakness in thought regarding the thing being argued for, where such purported weakness would be the real illusion.
The lack of satisfaction I feel when trying to capture my thoughts in English (my first language) isn't too far off from the lack of satisfaction at being able to comprehensively express a simple declarative in another language only because of the fact that don't know, say, the right word for the noun in that language. It doesn't lead me to agonize about how well-supported my observations about a backhoe are just because I've never been introduced to the word for backhoe in that language.