Wel....from the your grades on the professor's grading book (yes...usually they won't scale the grades till the famous shape is shown) to the electrical response in your brain, the famous Gaussian distributions (a.k.a normal distribution) cover most of the incidents that would happen in life. The most frequent events cumulate at the centre, and the rare events take place at the tail...only issues will be what do you want to define your variables.
I will demonstrate it in my next blog entry.