You should be very alert at all times not to play the wrong ball. In my many years of playing golf, this has never happened to me before. That is, not until that fateful moment yesterday while I was on an unbeatable winning streak. Just like that.
This is so easily overlooked, but it can sneak up behind you at the moment you least expect it and bite you real bad. That's what happened to me yesterday and probably caused me to lose my match. Going all square into the last hole, I went one down when my opponent sank a four foot par putt, after I lipped out mine. Damn.
In match play, if you accidentally hit the wrong ball, you lose the hole. In my case, it was not my direct opponent's ball, but the ball of an opponent of another pair two flights ahead of us. He had sliced his ball badly off of the tee and into my fairway, near enough to where I thought my drive had landed going the other way.
I wasn't a complete idiot though. I did bend down and check the ball. Indeed, I saw the Titleist logo, and right next to the number was the red dot I had dabbed carefully on one of the dimples. Only after I had reached the green, marked my ball and then started to clean it, did I notice my grave mistake.
I have no one else to blame but myself. I did check it though, but not 'carefully' enough. It was a Titleist indeed, not my number '2' but a number '3'. Also, the red spot on the dimple was not alone, right next to it (but unfortunately at the time of inspection out of view lying on the lower half of the ball hidden in the grass), were two more similar red spots, forming in total a simple crescent of three spots. Upon realizing my mistake, a felt an awful emptiness in my stomach, but had to confess right away.
Simply said, "Oops, wrong ball. You win." I scraped his marker from the green with the back of my Ping putter and flipped it in the air so that he could catch it. I ran back down the fairway and replaced the ball as best as I could where I had hit it, notifying the person down the other adjacent hole of my stupid mistake.
It was so easily overlooked that I do not feel so much ashamed as more screwed over. Oh well, bad luck. Where was my real ball? Had someone else picked it up by accident? Whatever, I learned my lesson. Fortunately despite my loss, the team as a whole had won. Otherwise I would have felt pretty bad.
I learned my lesson the hard way, so hopefully I'll remember to be extra careful the next time. Make sure that you never make a similar mistake.