Why don't kids learn to smell at school?

From a young age we learn to write lines, listen to music, paint landschapes and learn about touch through modeling clay or having fun with playdough. Yet, actively learning about one of the human body's most potent senses -the sense of smell- is strangely absent from most primary and secondary curricula around the world. Why? 

Smells govern our emotions, trigger memories, help us relax... When we eat, approximately 80% of what we describe as taste is retro-nassal olfaction or smell.