Hello, my name is Dan.
I will do my best to help you, the only stupid question is the unasked one.
My first suggestion is a pram reset. This resets the system and, if it isn't the mouse, should fix it.
If not then let me know.
To do a PRAM reset, you need to restart your machine and hold down these 4 keys all together at the same time.
‘Option’, ‘Command (Cloverleaf or Apple)’, ‘R’ and 'P' all together at the same time.
Keep them down until you hear 4 startup chimes, this is the sound that your computer makes when it starts up, it is like a boonngg. The screen should also cycle from white to black and then back to white along with the chimes.
The sound should also get louder.
This resets all of the system buses on your computer, USB, FireWire, display, ethernet and your keyboard/mouse/trackpad.
This will correct many faults but not necessarily yours.
Let me know.