Wow, I had a totally opposite experience than you did in school: exam questions were "dumbed down", made easier by allowing the use of calculators and reference books and cards, etc., and I'm told that that problem has continued to get worse. And, the teaching was all the same regardless of the student's apparent aptitude. Naturally, as an individual goes through school the questions become harder in keeping with the more advanced teachings, but that's the natural process of learning. We want to head in the "most difficult" direction if we want to get ahead and achieve our goals and dreams and, literally, just be able to survive as independent adults.
Also, many people don't take the "most difficult direction"--they remain average and unknown and contribute little to society. Walter Mitty types.
Some people take the 'most easy' direction, and they generally become criminals or addicts and don't have or achieve much, if anything, in society, in fact they take from society by abusing their rights, stealing, acting for personal gain or glory only, etc.
I think we should all WANT to head in the "most difficult direction" because that means that we are out to help the world as well as just ourselves. Helping the world means being kind to everyone, lending a helping hand, refraining from passing along gossip, etc. Random acts of kindness, extra unnecessary smiles to strangers, a greeting card to an old friend on their birthday... These are things that people do selflessly. And in the end, the "most difficult" direction becomes the easiest.