Terrible Twos

So I am quickly learning that the Terrible Twos don't actually wait until the age of 2 to unwelcomingly join the family.  Lately Yoyo is becoming more persistent (that's putting it nicely).  And when things don't happen on his command he resorts to throwing his body on the floor screaming "NO" like the world is coming to an end.  This leads us to today.  We ran out to pick up a few things and because he was being a good little boy he got to pick out a little treat (a single serving size bag of little crackers).  He held his treat while we finished shopping and would repeatedly ask me to open it but I would tell him he had to wait until we paid for it.  He even willingly gave it to the cashier and let her scan it and put it in the bag.  So far, star performance.  We get to the car, I buckle him in, I grab the treat bag, and go to hand him a couple of crackers....and instantly the kid lets out this blood curdling scream, so crazy and loud that I actually for a second thought something was wrong.  He screamed and cried and threw the crackers back at me.  I realized then that he wanted the whole bag but this little momma didn't want a car full crackers (long road trips only!).  He continued screaming like I've never heard before and people walking by the car were looking with concern, I'm sure wondering if I was beating my kid in the back of the car.  This lasted for a good solid 5 minutes (which may not seem like a long time but my poor little ears will tell you it felt like forever).  And then just as suddenly as started, it stopped.  Then I heard this quiet little "tinktoo" (thank-you...he gets the order of please and thank-you a little backwards some days) and so I handed him a cracker and all was well in the world again.  I know I'll be jinxing myself but I am soooo thankful he has yet to do this in public.  It is frustrating and embarassing!  Nothing makes you feel like a star mother when you're child is acting up in the open, judging, eyes of the public!