One of the things good to keep in mind. Always.
Yes, most of us hide somewhere around the fat middle, but never, ever, forget that the "thin ends" which extend to infinity, or at least to the extent of your sample. And yes, not every bell curve is as nicely symmetrical as the one shown here, but it will be a bell curve nonetheless.
How tall you are, how fat you are, how rich or how poor. What's your sexual preference, how religious you are. How good are your eyes, how far you can throw a mobile phone. When you plot a trait against how many have it, you get a bell curve. Always.
Why is this important to keep in mind?
Because it is all too easy to cut short the "thin ends." And that is bad. That makes people drop off the edge of (your) world. A lot of people. Because the "thin ends" may be thin, but often they are long, much longer than most people think. And this means a lot of people cower underneath.
Let's not forget about the "thin end" people.