The only explanation I have is that the general difficulty is slowly going downwards. I was in school in two different countries (France/Germany) and on both sides there were some similarities, a shortage of funding and said funding being dependent on the number of people getting through the system.
So you have this sort of pressure that acts on the difficulty, since if the difficulty is too high less people graduate.
Then you also have the accomplishment of those before us. I remember looking at things from tests a few years ago, I would not have been able to solve that. (They were tests on mechanical forces.) What we were doing was a lot simpler, yet most did not realize this. So you have this idea that those that came before us were 'less smart' because we are acing it without much thought!
Obviously I only have a picture of my immediate surrounding. I've been in school from 2000-2014. Am currently studying. Perhaps someone from earlier or later could give their point of view on that matter?
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On another matter, I really dislike how my current reward system works. Am trying to fix it by eating regularly, something that looks like a sleep schedule, and actually giving a shit about the stuff that I produce.