This first one is my favorite, though it may not be true with recent developments in non-stick coatings.
As I said, this may change since a college student has developed a coating for bottles that leave little to no residue in the bottle. Here is the video of the bottle in action.
That is really sad that 15% of people in the US over 5 years would not have died because of smoking. Imagine if people actually did stop smoking..
This next one is really relevant to me because I crack my knuckles a lot.
So the fact that I can crack my knuckles constantly isn't necessarily bad for me, but rather bad for you, assuming that you don't like hearing it. I'm not saying that I'm going to be a jerk and do it all the time, but I probably won't reduce how much I do it (which isn't that often).
Finally, this last one I just found interesting.
Who knew (other than cartographers)?
Have a great day!