not know A from a windmill

To be stupid. It references the vaguely similar shape of the letter A and a windmill. How do you manage to burn pasta? It's like you don't know A from a windmill.

Common Names:

Name	Pronounced	Usage
Kulap	-	Thai
Manaem	-	Biblical Greek
Rosmunda	-	Ancient Germanic
BlÁThnat	BLAW-nit	Irish, Irish Mythology
Ace	[eis]
TomÁŠ	-	Czech, Slovak