You know that show "how i met your mother"? well, on one of the episodes, they call it "the last cigarette ever" but they dont stop then, and then the next time they try to quit, they call it "the last cigarette ever" and it keeps on like this until they finally do eventually quit.
THATS how i feel about trying to stop drinking soda. It's like "last cigarette ever" syndrome mixed with "i'll start that diet on monday" syndrome. I always want to get in just one more and start next time.