Will someone give me proof golf is a sport! My friends are idiots...?

Okay so i posted on Facebook that if Tom Watson wins the open it will go down as one of the greatest accomplishments in the history of sports. Not long after i got a few phone calls from friends claiming i was a moron and that golf isnt even a sport. I remember watching something on the golf channel the other day explaining why golf is a sport and i remember saying Eff yah about time someone got it right. I cant seem to find that video anywhere nor any articles explaining why golf is a sport. I dont get how golf is not a sport. you have to have great hand eye cordination, your walking miles every round, your hitting a golf ball with a stick at over 110 MPH in some cases, the more athletic the golfer the better they usually play. so how are golf not a sport? Can someone give me some really good ammo to shoot back at my friends who keep ripping me for loving golf so much.