If I think about it, I have been really good at two games.
The first was Starcraft/BW. When I first joined battle.net, I had known a guy in a clan... I think it was [WS] or something. They were ok and I was an average player. Then that clan merged with another clan that was from South Korea and their leader was in the top 10 of the Korean Ladder. We then had some training games and he shows us how to play Protoss. So we worked that way for awhile but since there was such a time difference, we didn't end up playing with them very much. Also then everyone (the US people) left the clan or stopped playing Starcraft. I was then on my own and decided to play on the NA Ladder. I went 35-0 and then quit.
The second was Quake 3, which I played for much longer. I had mastered the strafe jump fairly quickly and then the rocket jump. Also a different way to aim, where you put your mouse sensitivity all the way up. Then you can look around very quickly. And you can time it in such a way that where you can do a 360 (or less, whatever) very fast by lifting the mouse off the desk slightly and then put it down to stop the turn. I kind of learned this by accident when I went from using ball to optical mouse around 2002. This trick can only be used with an optical mouse, it does not work for a ball mouse.
So this way you end up moving much faster than everyone else, but then you also get blamed for botting. Needing more challenge I left the normal arenas (and Urban Terror) to play on rail servers. Then I moved entirely to jump maps, or what became known as parkour servers, which were all about using the speed tricks where I then finally figured out how to do plasma walking. These types of servers all had maps where you needed to use the tricks to move around, the platforms and jumps were in some range outside of a normal jump. It was popular for a short time, but the amount of people playing Q3 was falling and most people who joined those servers did not know how to do this, so they camped a lot. I then ended up moving to speed servers like Vogon. This type of server was modified to make the game run faster than normal. This is the end of the story, having gone to this type of server, you cannot go back because normal speed is too slow. My best achievement was playing in the tournament that lasted for many hours. I made it to the final match and lost vs Russian (his name, he was from Russia).
Since having those experiences, and the amount of time it took of my life playing. Especially Quake 3 where you can get "rusty" from not playing daily, I have not had the motivation to be "good" or competitive in any other game. Now I just play them for fun.