At around 40, I&#x27;m now learning things like math quicker, but then I forget them a year later, whereas the things I learned in college I still remember now.<p>Is this normal, I wonder?<p>You might say, well, if you&#x27;re forgetting them a year later then you didn&#x27;t really learn them, but I disagree.  I feel more complete mastery of a subject matter more now than I did in my teens.  No, I forget things I learn much more quickly now, and the only way to not forget them is to practice them at least each week, and that rapidly becomes a time sink.