Having a lot of RAM nowadays is relatively cheap and Linux can make a good use of it. With tools like preload most of Linux distributions are trying to proactively read things that you might want to use soon.
However if your desktop have a ridiculous amount of memory (mine has 32GB) it may take ages for these tools to make use of all that memory. And why would you pay for it and then let it just sit idle instead of working for you?
The thing is: you can do much better, because you know what you are going to use in the future.
So, as always, let’s write a tiny script under the name precache.