Like most good photos, a combination of luck, experience and skill is required, it's just the ratios that change. If you have the only photo of a crashing 747 because you were taking an iPhone snap of your wife and the plane crashed in the background you were 100% lucky, if you make a masterpiece of a green pepper in the kitchen you are 100% skilful. Most photos are somewhere in between.
Obviously the luck in this case is quite literal, you have to win a lottery (and after setting a date months in advance it had to rain the day before maybe), but having won how many people on that same day made as good a photo? Of course we'll never know but I suspect "not many" would be the answer. Then it's possible experience came into play, if you'd been there before you may have a good idea as to what it will look like and rush to get the shot before the crowds arrive, or you may know that the sun will cast a crap shadow at around 11AM, or you may know that a pool forms in a particular spot and it's likely to be usable to get a reflection of the monuments.
Finally when luck and/or experience places a scene in front of you skill and an "eye" are required to make the most of it.
So at the risk of this becoming a mutual-admiration society well done Oksana.