be wearing [teacher's etc.] hat

be wearing your [teacher's/lawyer's etc.] hat

also have your [teacher's/lawyer's etc.] hat on

to be acting as you do when you are working as a teacher, lawyer etc., which may be different from the way you act in other situations I was wearing my teacher's hat at the meeting.

Common Names:

Name	Pronounced	Usage
Fionn	FIN, FYOON	Irish, Irish Mythology
Arjuna	-	Hinduism
Bernard	bər-NAHRD (English), BUR-nərd (English), ber-NAHR (French), BER-nahrt (Polish, Croatian)	English, French, Dutch, Polish, Croatian, Slovene, Czech, Ancient Germanic
Finbarr	FIN-bar	Irish
Mikel	-	Basque
Samira (1)	-	Arabic, Persian