Why is it that my mom wasn't surprised that she was ticklish on the other spots but when it came to her pescoco she was very surprised that it was ticklish and she laughed and said, "ha, no pescoco!"

Ticklishness can vary from person to person and can also depend on the sensitivity of certain areas of the body. Your mom likely had previous experiences that made her aware of her ticklishness in many areas, but the neck (or "pescoco," which is Portuguese for neck) might not have been one of those areas she expected to be ticklish. It's also common for people to have surprising reactions to stimuli in areas they don't often think about. The neck is a sensitive area for many, and it might have caught her off guard, leading to her surprised reaction and laughter. The element of surprise often enhances the tickling sensation, causing people to laugh or react unexpectedly. So, her surprise was probably a mix of her not realizing that area was ticklish and the unexpected sensation triggering a playful response!