Out of " All the fish in the sea" a " Nemo" is that one person your crushing on or chasing after.
Girl: " Just like Marlin in " Finding Nemo" I have found my Nemo out of all the fish in the sea."
Other girl: " They may say there are plenty of fish in the sea, but Chad is my Nemo. "
When something happens in real life that would be perfect in a cartoon or has happened in a/ or many cartoons.
Guy: " Yesterday I slipped over a banana peel, it was a perfect cartoon moment!"