This is the first panel of the Calvin & Hobbes comic strip published on 7 July 1986:
I foresee my lovely spouse having this same conversation with our daughters. To paraphrase a conversation with my younger brother in which we reflected upon our childhood:
Bro: I used to think you knew everything about everything. Finally, I realized that you just made stuff up.
Moi: Yes, but I said it with confidence. . .