Anyone who has seen Jackie Chan's adventures can't forget this sentence from his father now. )

For the plot. Dad may say this to remind you, or he may tell Jackie Chan that something new has happened.

In order to shape the characters.

(People who have seen Jackie Chan's adventures now think of Dad, and they will think of One More Thing and Monster Leave.)

In order to conform to the stereotype of the elderly in society.

(In line with the stereotype, at least ensure that it will not be sprayed too hard here? )

It may be a script made on a whim or it may be the result of careful consideration.