M is for Motto
One day, when my brother was about 5 years old, he randomly started saying “As I always say, ‘Do the hard part first!’” (To be clear, he didn't actually go around saying ‘Do the hard part first!’ in preparation, he just started out by insisting that he habitually said it.)
The saying applied in a number of situations: eating your vegetables before dessert, cleaning your room before you watch TV, etc., so he got a lot of chances to use the phrase (again, always preceded by “As I always say . . .”).
We never understood where this sudden propensity to quote himself had come from, until one day, many years later, when we reminded him of the behavior.
He remembered doing it, so he explained that it was because he used to watch The Magic School Bus on PBS and Ms. Frizzle was always quoting obscure relatives of hers. (E.g., “As my Aunt Minerva used to say, ‘there's nothing more marvelous than mud.’”) So he decided that he wanted to have his own motto, too.
It’s a pretty good one.