Your child has just emitted a real verbal treat and you then had the immediate desire to archive it in the long term?!
As there's nothing else handy, you take a scrap of paper, perhaps even a sticker, or you have actually already earmarked a notebook for this purpose which just cannot be found at this very moment... (never mind – you can write it down later).
Some time after this (unfortunately, you had to do some urgent work, your child was rather fretful, or something else occurred), you find that the piece of paper was thrown away, the wind blew off your sticker, or the notebook miraculously turned up again, but, even though you tried hard to remember, the saying just vanished from your mind.
Everyone who's experienced a situation as described above can create an account free of charge on this portal and thus archive these priceless children's sayings: