Computer trouble
I was having trouble with my computer. So I called Eric, the 11 year old next door, whose bedroom looks like Mission Control and asked him to come over. Eric clicked a couple of buttons and solved the problem. 
As he was walking away, I called after him, 'So, what was wrong?  He replied, 'It was an ID ten T error.'
I didn't want to appear stupid, but nonetheless inquired, 'An, ID ten T error? What's that? In case I need to fix it again.'
Eric grinned.... 'Haven't you ever heard of an ID ten T error before? 'No,' I replied.  'Write it down,' he said, 'and I think you'll figure it out.'           So I wrote down: I D 1 0 T 
I used to like Eric,  the little bastard!

MOUSE CALIBRATION
You should actually do this every year. Even more often is recommended by Kim Kommando (the computer guru) if you spend a lot of time on the computer.
I was shocked to see how well this works, and how far off mine was!
To re-calibrate your mouse, click and hold on the Y below, then drag the Y toward the g. If it doesn't work immediately, you might want to clean your mouse, as the calibration is off.