I learned about sex from George Michael. Some might say that explains a lot, but I pride myself on having never been caught with my pants down in a public restroom. It’s mostly notable for the fact that my poor mother had to explain to her eight-year-old son what “monogamy” meant after Michael wrote the word in red lipstick on the back of the singer’s then-beard/girlfriend Kathy Jeung. “It’s when a man and a woman are married,” she told me. Good try, Mom. Forget the denimed butt shot of the “Faith” video that would follow a few months later; for millions of men, women, girls, boys, and everything in between, “Sex” was the moment that Michael went from pastel-colored gym-short-wearing, feathered-haired fruitcake to bona fide ‘80s hunk. Those squelchy, orgasmic synths and stiff beats (all instruments, the liner notes told us, performed by the manly and capable hands of Michael) provided a horny bed for the former Wham! singer’s faux-masculine growl and calculatedly impatient come-ons. It was the older, more sophisticated cousin to Paul Lekakis’s “Boom Boom (Let’s Go Back to My Room).” The same conservative puritanical thinkers who decried the controversial song and video 20 years ago would, given what we know of Michael today, probably now applaud his promotion of a healthy, monogamous, hetero relationship. “Sex” may not have been Michael’s biggest hit (it stalled #2 in the U.S.), or even his best (for that look to pretty much everything on Listen Without Prejudice), but it’s unquestionably one of his most memorable and defining moments, and, in the progenitive years of AIDS, it was one of the few times when Michael’s outspokenness (“Explore monogamy” was the music video’s ultimate missive) was actually Important to someone other than himself. Why am I spending so much time talking solely about one song, you ask? Because it’s dubiously, disappointingly missing from Michael’s new greatest hits package, Twenty Five, which is essentially just an update of 1998’s Ladies & Gentlemen: The Best of George Michael capitalizing on the singer’s first stateside tour in 17 years. And the omission of “Monkey”? Well, that’s downright criminal.