Regarding Hermione Granger ~ "She's kind of a know-it-all", but you really should listen to her".
"Mom, this lip gloss I left in the car last summer and it melted? If we put it in the freezer would it get solid again?"
"Sorry, no, it doesn't work that way."
"Oh. It must be an irreversible change then. Growing up is irreversible change too."
When faced with the word "tenacity" in a children's show, and told it means "never giving up", she asked, "Wait. Isn't that perseverance?"
"Do they call these Kix because theyah shape like balls? Foh kicking?"
When using a word nobody had heard her use before, and asked, "Where did that come from?" Her answer? "Fwom my mouth." With the unspoken "duh" in that tone. You know the tone.