Takin' this stranger thing a little overboard

So apparently Griffin has been learning about strangers in school because anytime I say hi to someone walking by the house, Griffin reminds me they are strangers. He said strangers are people you don't know, which is right, but it is getting a little crazy. At Walmart the other day while giving my money to the clerk, Griffin announced "danger stranger" to her and myself. I tried to shoo him off for a sec and when we were leaving he told me that I wasn't supposed to talk to strangers. I told him the lady wasn't a stranger and he said "well do you know her?" I said yes I do because she is the lady who takes my money and he seemed ok with it. Wonder where I will hear it next. Guess this safety stuff is good but was a little embarrassing since he doesn't have the quietest of voice.