Have you ever just walked out of a store leaving your cart with items in it?

Yes. It has been a long time, though. I swear there have been times when the check-out clerks would just be so bad at their job, I couldn't stand it any longer and just left.

I can only recall having done that when M'ija was little and having a temper tantrum.

If I've gone to all the trouble of filling the cart,I;m not wasting the trip by leaving it all there just because the line is long.

Only when ds had a major diaper blowout and I was not equipped to handle such a large undertaking outside of the well stocked area surrounding his changing table at home. I did get a shopping bag before I left to tie around him to keep it all somewhat contained though. Aaah the cute little memories that will haunt you until the day you die.

yes once.

DS was 3 years old and DD was a few weeks old and he threw the mother of all hissy fits and we left it all and went home. i went back with DD later on and shopped.

Only once, but it was just a few items, not a whole cart full of stuff.  I had bought something that, according to the price on the shelf, was on sale, but it kept ringing up the regular price.  I kept telling the cashier that it was on sale, but he refused to believe me and wouldn't go back or have anyone else to back and verify the price.  He had a bit of attitude and he was making me mad, so I just said "Fine!", left all the items at the register, and walked out of the store.  I felt bad because there were some people behind me in line, but he embarrassed me and I had gotten too frustrated to think clearly.  

Yes