I have one that my son left for me in the lab when he was about 4 YO.

He misspelled "dad" as "ada". When his 6 YO sister pointed it out, he fixed it. It became:

ADA
DADA

Still have it somewhere. Occasionally, that is still my name.

If you take the time it takes, it takes less time.
--Pat Parelli

American by birth; Alaskan by choice.
--ironbender