If you know me to any degree, you're well aware that I can talk for hours upon hours about music, musicians, bands, albums, the music industry, instruments, recording techniques, music history, etc. If you start me up, I'll never stop (thanks, Mick).
However, time and place are important factors. I openly invite anyone and everyone to chat me up before or after a show, and I'm almost always happy to have a quick exchange with fans, friends, or both between songs in a set (if it's a QUICK exchange clocking in well under 5 minutes, not a recitation of Homer's The Iliad) and provided it doesn't happen between every other song I play.
Content is also important.
Beyond that, frequency is the final element to be mindful of. I already mentioned the "Oh, he just ended another song... must be time to go talk to him again" issue, but try and keep track of who you've told your story to. You got drunk in Minneapolis and somehow bumped into Prince, got nervous and puked all over him, only to laugh hysterically when you saw it was purple? Awesome story... the first 12 times. Now it's just kinda annoying (and a biohazard now that I think about it).
So tell me what's on your mind. But keep it brief, on topic, and timed properly.