I have never understood the concept of "off topic"
Isn't a conversation the exchange of ideas and thoughts that ebb and flow ?
Maybe I am wrong, but when you conversate with someone, your thoughts and the subject takes on a course all by itself, it goes where it goes then it comes back to where it was.
Could you imagine, sitting in a cafe, talking to your buddy.
only to have someone tell you not to comment on the butterfly that fluttered by
because it is not on topic with the bridge you are discussion?
https://www.youtube.com/watch?v=ZRLRmQGhL9Y
Where was I ? Oh yeah. Butterflys. Aint they pretty?
http://www.bing.com/images/search?q=butterfly&FORM=HDRSC2