E.R.
I never had a problem with my son when we went shopping, but one particular day when he was 3 years old, we were on the shampoo isle, and he wanted the Loreal for Kids shampoo. I told him no, and he threw the fit of all fits. This included laying in the floor, screaming, crying. I simply walked away. I walked over to the next isle, where I could still hear him, but was out of eyesite. It took about 2.2 seconds for him to realize Mom's not standing there, and he stopped. As soon as he stopped, I walked back around the corner and asked if he was finished. I never heard a peep after that!