(Free**) Days are not boring. (Free**) Weekends are not boring. They just mark the passage of time...
As
@Ian H hinted at, there are millions of books to be read. Or books of your own to write?
Millions of pieces of music to listen to, or to play, or instruments to learn to play those pieces yourself. Or pieces of music to write?
Amazing places to cycle or walk or run or drive or kayak or [insert means of transport of choice here] to...
There are a few interesting websites to go and check out too!
Many tricky puzzles to solve, or your own puzzles to create.
And thousands of other ways to keep your mind occupied...
The problem isn't finding enough things to do, it is finding enough time and energy to do them!
** If you have a really awful job that you have to do, or you are locked up in solitary confinement without books/a computer/a musical instrument, or with really boring people that you can't reasonably escape from, yeah
THAT would be pretty boring!