know the first thing about

not know the first thing about something

to not know anything about a particular subject I don't know why you're asking Rob, he doesn't know the first thing about classical music.

Name	Pronounced	Usage
Aulis	OW-lees	Finnish
Bellatrix	-	Astronomy
Eirenaios	-	Ancient Greek
Karolina	kah-raw-LEE-nah (Polish), kah-ro-LEE-nah (Swedish, German)	Polish, Swedish, Norwegian, Danish, Hungarian, Slovene, Croatian, Macedonian, Lithuanian, German
Heidrun	-	Norse Mythology, German
Marlis	-	German