shape of my heart

Every time when I listen to the song called <shape of my heart> I feel so sad . This is the theme song of the famous movie <Leon the professional >,which tells a moving story about a  professional assassin rescues a young girl whose parents were killed in a police raid.This is a sad story because the killer died together with the bad police in the end ,and the little girl has to live alone ever after ,with the only thing he left her --his favorite plant.I like all kinds of movies as long as they are worth -watching ,and this killer type is absolutely my first choice.Just like art is made of contrast and controversy ,characters are made of two sides too .A man can be warm -hearted and cold -blooded at the same time ,ain't it the most interesting part ?
I 'd like to share the lyrics with you all.

I know that spades are swords of a soldier 
I know that clubs are weapons of wars 
I know that diamonds means money for this art
But that's not the shape of my heart