I was teaching a friend how to shoot and operate his new glock a few months ago that he got for his birthday from his wife. After he loaded the entire magazine, he showed it to me and asked if it looked right. All 15 rounds of. 40 were loaded in the magazine backwards. I didn't know it was his first experience with a semi auto....
Reminds me of this story; http://www.thefirearmblog.com/blog/2013/05/08/hk-bullets-real-story/