Isn't EXPERIENCE the best instructor? I don't get it.
A president who has never been in battle never been in war never even served his/her country in the military having power over the lives of millions and playing them as if they are pawns on a chess board? Seriously?    
An unmarried marriage counselor.  They read a few books, passed a few tests, and got a nice certificate to hang on the wall.  Yep, having that certificate makes them 100% qualified to solve any marital problem that will ever arise. 
Some things take experience in order to understand.  It’s rather hard to walk a mile in another person’s shoes if you never put them on.  How can a person who has never been married fully understand the problems of those who have?  Sure, they may know a few things (book smarts), but without actual experience they’re unable to sympathize.  That sympathy is what makes a good counselor.  They’ve experienced pain, heartache, frustration (etc.), and have firsthand experience as to how it truly feels.  Book smarts can’t do that.  Book smarts say, X+Y=Z.  Therefore simply do ‘z’ and you’re cured.  In reality, rarely do X and Y=Z.  There’s always more to the equation.