Nineteenth century horsemen noticed how cautious free horses naturally were.  Horses voluntarily take no unnecessary risks.  So horse sense means thinking before acting and taking the cautious approach.  Lately, it's also come to mean common sense.

Why are horses so "spooky"?

Being prey affected horse development and behavior.  A horse's primary defense mechanism is running away.  They will put up a fight when frightened and cornered.

How are the horse's senses different that humans?

Horses have five senses but they are developed in a much different way than humans.

• Sight - A horse has about 330 degrees of horizontal vision.  Given that a circle is 360 degrees that's pretty amazing.  A horse's blind spots are approximately 15 degrees of arc directly in front and 15 degrees of arc to the rear.  Horses have binocular vision when they can raise their heads and "look down their noses."  As a result they have poor depth perception when properly "collected" and must trust the rider.
• Hearing - Horses' hearing is both sharper and broader in range than humans.  They may start at unfamiliar sounds, but will usually investigate and remember the sound.  Since horses hear better than you do, it doesn't make sense to yell.  Use the tone of your voice to let him know how he's doing.
• Smell - Horses have a well developed sense of smell and identify individuals by their individual odor.
• Taste - Horses can distinguish sweet from salty and individuals develop preferences in food.  One owner described her efforts at getting a gelding to eat carrots.  She shaved them and mixed them with his sweet feed.  She returned later to find bits of black carrot crumbles pushed to the side of his food bin.
• Tactile - Horses are extremely sensitive.  A 1500 pound mare can detect when a fly lands on her hip.  Horses investigate things on the ground with their hooves and noses, touching them as they smell them.  Their whiskers help them find good things to eat.  Strokes and scratches are certainly appreciated, gentle pats are nice too.  Sharp pats are hitting and no one likes that.

How smart are horses?

Horses have been intellectually equated to a human child of three to six years of age.  The problem with this analogy is that horses are not human children.  They are sociable creatures and learn from their experiences.  Some are more adept at learning than others.  As you learn things about horses in general, it's always a good idea to remember that each new horse is an individual and may respond unexpectedly to your directions.

What is so special about novice?

Novice is a "closed" class of competition for both horses and riders.  The novice class is a safe place for new riders and horses to learn.  Generally, any horse or rider that has earned three or more first places in a class for a given show rating may no longer compete as a novice.

Is an amateur always a novice?

Many amateurs are very accomplished riders.  The definition of amateur relates to the percentage or amount of income a competitor makes from horse-related activities.  Amateur is not a rating of skill.

Are professionals always the best riders?

No.  As in amateur, the definition of professional relates to the percentage or amount of income a competitor makes from horse-related activities.

What is an open?

As opposed to a closed or novice show, the open is open to all competitors who have earned three or more firsts in that class.  Luckily shows are rated as well, so someone who has just graduated from novice at a local show level won't likely be competing against the national champion.  On the other hand, the national champions have to start somewhere.  (In the novice ranks...)

What is a balanced seat?

It's what it sounds like.  The rider is balanced on the horse so that she won't fall should the horse suddenly misstep or shy.  The rider does not need to grab the reins for balance when the seat is balanced.  The rider's seat changes to match the horse's gait.  A balanced seat is nice for the horse too, she doesn't have to worry about the rider hanging all over up there and can concentrate on the work out.

What is collection?

The horse is collected when her forehand and her hindquarters are united.  She is ready to move in any direction and at any gait at the request of her rider.

What is conformation?

Conformation is the horse's build.  Each breed has conformation standards by which the breed is judged.

Can those whisperer trainers really get a wild horse's attention in a few minutes?

Yes, but it's what you do with that attention to develop a relationship over the next several months that counts.