Latin has ruined my view on finding nemo

Nemo means nothing in latin
Does this mean that nemo never existed? Did he actually die along with his mother and other siblings? What if Marlene was grief stricken enough to create his own imaginary son. Cause literally everyone in the movie was crazy in their own way that would fit the archetypes of those who would be in an mental hospital.

the most significant thing i learned at school today is that testes/testicles are called such because in ancient times only men could bear witness in court, and a witness was called a testis, and they had to hold their nuts while they spoke because they were basically swearing on their junk