Return of the childhood

Today I observed an intriguing incident at a restaurant over lunch.
A grandmother entered the restaurant with her daughter’s family including 2 young children. She sat down at the table next to me first and ordered a slice of apple pie with extra vanilla ice cream on it. She told the waitress that it was her very favorite. She then proceeded to eat it with a childlike eagerness when her food arrived before other family members ordered their food.
I recalled some people told me that when people get older (probably into their retirement), they sometimes behave like children. I have no intention of picking on more mature people (we are all heading in that direction). I wonder if we let go our inhibition and be more carefree, we may be able to learn faster like children do.