yes, I have actually, I remember wondering that when I was very young. I thought if it could suck in all that stuff, there must be some place on the other side with all it's sucked in.
About that "why people repeat themselves?" I would imagine it's because they think no one heard them or they weren't heard by whomever they were speaking to. Not a big deal. Just acknowledge them and it should stop.
Do you ever wonder why people have such difficulties understanding one another sometimes?