I have had almost the exact same conversation with an acquaintance at work at least three times in the last month or two. It goes something like this:
Acquaintance: How's that baby of yours? Walking yet?
Me: No, but she rolls all over the place!
Acquaintance: My oldest son was a little Tootsie Roll. I think he's an alien. I swear I was impregnated by an alien.
Me: [awkwardly laughs] Oh, really?
Acquaintance: [launches into story about how her son used to crawl backwards and then one day stood up and walked down the stairs and now he can understand any game after reading the instruction booklet for one minute]
Acquaintance: And now he's in the Navy!
Me: That's great! Well, bye! [gets the heck out of there while simultaneously wondering if this lady actually thinks she was impregnated by an alien]