Compiling error. Doesn't think I'm including libraries that I am.

(I’m pretty new to this so please give me a break if this is a really dumb mistake.)

Okay so I was messing around on this website and came across the Mouse library listings and thought it looked interesting. I wrote up a little thing that would just spam clicks when I pressed a button.

#include <Mouse.h>
void setup() {

void loop() {
  int x = digitalRead(2);

However, when I tried compiling it, I get the error

exit status 1
‘Mouse’ not found. Does your sketch include the line ‘#include <Mouse.h>’?

It finds a problem with both; and Mouse.begin();. I don’t understand at all what could be going wrong. I can compile and upload to the board if I just exclude anything related to the mouse library but when I try to include it it does this. No idea what could be going wrong, everything seems fine. I’m on Win10, Arduino UNO R3.

I'm on Win10, Arduino UNO R3.

From the mouse library docs:

These core libraries allow a 32u4 based boards or Due and Zero board to appear as a native Mouse and/or Keyboard to a connected computer.

It only works with Leonardo, Due, and Zero boards. Won't work with an UNO.

This is why reading is such an important part of coding.