Quick question for writers/students/beta readers

Did everyone know about the Track Changes funtion in Word except moi? It's changed my life. If there's a sizable # of people who don't know about it, I'll give it a wee write-up because it's invaluable if someone's editing/proofing/giving feedback on your writing.

But if I was living in the Dark Times, then just color-me-happy and we'll move on. I learned of in February when I started doing online tutoring.

(It exists in OpenOffice and other Word-esque programs, for those who can't afford Word, or use Macs.)