When I was pregnant with my first child:
lady in line behind me at the grocery store: mmm. Your butt spread. You're having a boy.
me: I'm 5"1'--where is my butt supposed to go?
Now, she had never met me, never seen my butt before (and why exactly was she looking at it?!) so how did she know it had spread?! And, for the record, it was a girl.
A few months ago, with my then 3-mos-old:
cashier, peering at ds in the sling: That's a very interesting...thing. Is the baby comfortable? Does he like that...thing?
me, trying to pay her: yes, very much.
cashier: I dunno. How do you drive with him like that?
me, now trying desperately to leave: Um...I put him in his car seat.
cashier: oh. You take him out of that. Of course. His car seat.