Blog text howlers

Cool yard time 

What is it about writing a blog that suddenly
turns a hitherto immaculate text content 
editor brain (mine, haha) into a text designer 
brain (not mine), focusing on word sound 
rather than spelling and making more than 
a few grammatical errors along the way 
that then have to be corrected?
It's frustrating and I throw the topic

open for general discussion. Is it that 
blogging consists of what is in effect a
stream of consciousness first draft which, 
because of the speed and immediacy 
of the medium, we tend to think of as a 
final, publishable draft? I'd be interested
in others' thoughts.