So did I.
I had the same thing at age 4 in the store, my mom would grab the blue and white box and I would get scared, but I was still in cloth training pants and only had to wear plastic pants at night or naps. One of the times we were in the checkout and the the lady checking us out held up the plastic pants box and said to me are these for you? I did not say a word, but when we were just leaving my mom said said come on lets go home and try on your new plastic pants.