Is it wrong to judge a book by its cover?

During the early phase of my army days, I managed to leech something interesting from my platoon commanding officer. He dragged me into his office one day for a one on one counseling. This bastard probably have high hopes on me assuming that I was the only one he took 30 minutes to counsel. He told me about this particular platoon mate who has tattoos all over his body but is a good friend of mine. He told me this line that I will never forget," Woi, Apache, (my nickname) a person's tattoos say a lot about the person's character. You see the person's tattoos and you will know it."

My friend's tattoos was typically a mixed of all sorts including birds and Beckham's trademark left hand tattoo and some other weird stuff. Individually, the tattoo looks nice. However, as a whole, it was in a mess. Although he is always sociable joker, its undeniable that he saved my ass a few times.

This lead me thinking. Was it really true when they say never to judge a book by its cover? Or was it really just referring to books? My conclusion is that this statement is only true to a limited extent. The way we dressed up usually reflects our sub-conscious thinking and behavior. So, it is possible to judge some one by his dress code, his appearance. Instead, I think what this statement meant was that never to judge a person by his god-given appearance.