You probably shouldn't ignore it (note to self)...
The other day, when I got my 29er out of the back of my van to ride it outside the hotel we were vacationing at, I heard a sickening thud when I put it on the ground. Looked around a little at "stuff", dropped it a little bit on the ground again to see if I could produce the same sound. I heard it again, looked around a little. Hmmmmm.
Got on, started riding. Same whirring/humming/rubbing sound that I noticed a little on my previous few rides, thought, "must be the disc brakes rubbing like I read about on BF". Kept riding.
Up hills, down hills, around corners on dark roads through the woods with no shoulders on unknown highways. No events, but still not liking the humming. Forgot all about the thuds until I picked up my bike to put it back in the van after a less-than-satisfying 8 mile ride...
and the quick-release rear wheel fell off. Gulp. All those times I stood up to hammer it up the hills... yikes.
Perhaps I should actually look at my bike before I ride it, and not dismiss new sounds as, "that one thing I read about on BF".
You'd think I just started riding...