Talking only with people in the field, so when you say "The thing does the thing with the thing", they know what you mean.

Nah, if you are an actual researcher dealing with hundreds of species you hardly now the common names (if the taxa even have common names, which most don't!). Also, working in a diverse international environment like the research community means that knowing only common names won't get you anywhere. It is very much necessary for you to know scientific names to be able to communicate with others.

I know many the scientific names of taxa from completely different kingdoms than my own research because I've been talking with other researchers about their field of study.

Real experts know and use a variety of names and consciously choose the best one for the specific context and audience in question.

"No, that's a roly-poly. Not a vulgar armadillo or whatever the fuck you just said."

Love this! lol