That's interesting. How long have you lived in NYC, and did you move from a very small place? I mean I agree once upon a time they may not have been that well-known. I can remember in third grade (1969-1970) a mention was made of them in our Social Studies Book. My teacher, bless her heart, was from the area. I don't know how much travel experience she had. But bagels were probably not a common item in a smaller (but not small) Texas city with a population of about 150,000 (49 years later the population is a little over 250,000). She pronounced them as if the a-sound were like the "a" in apples. Of course being in the know, I had to raise my hand and share my knowledge with the class that the a-sound was long like the "a" in bake.
There were probably about 6 of us who were Jewish in my elementary school. There was one other child-a girl-in my grade. But I can't remember if she was in my class or the other third grade class. But she never drew attention to herself about being Jewish at that age as far as I can remember. So I was the only one who would've corrected the teacher. Of course T (my fellow Jew) ended up marrying into a very Orthodox family and has probably been much more observant over the majority of her life than I have been.
Gman