Could it be that you've exhausted the easy things to learn? I feel that at some point it gets hard to keep the same learning velocity as the knowledge you are a

Could it be that you've exhausted the easy things to learn? I feel that at some point it gets hard to keep the same learning velocity as the knowledge you are acquiring gets more complex and difficult to grasp. Also major breakthroughs are much rarer. While learning things similar to previous subjects seem trivial. Learning new programming languages for example. Once you've accumulated enough of then pattern start to repeat and learning the next one becomes more and more trivial to the point where it doesn't feel like learning the same amount of stuff as previously.