I tend to rely on talent to understand almost "from the box" any game mechanic thrown at me, be it the infamous "cover system" or the "run and gun" more obvious one, or the FPS strategy of "let them waste amo and run to melee them to dead" kamikaze style (wich is fairly good to make your opponent scream like a baby)
but once i start to not give a damn about the game, my skills start to decay, i know every twist and turn on the game, and it stopped being funny like 2 years ago, so i just stop and move on
but if i ever go back to that same game a few years back, i suck at it, seriously, its like i never even played the damn thing, i know everything there is to know about the game, mechanics, maps, anything, but it just got to the point where i cant do a damn thing right!!!
some say its lack of practice, but even if i spend the next 3 months playing day by day that same game (wich is torture because i already know everything there is to know on the game) i will not get better in a visible way
oh!, but i´m kicking ass in the new game that came out 3 days ago
i guess its more in line with "keeping my mind estimulated with new things", because once its old, i get bored easily
it goes like this, "the game is new, i like it, it keeps me interested, i learn from it, it starts getting boring, i get to know everything there is to know about it, i move on to a new game" and the cycle repeats untill i find a f%&king awesome game like TLOZ:OOT or TLOZ:MM, games that i just have to play once a year or i feel i wasted a year.
EDIT: ANOTHER GOOD EXAMPLE is that i finished Rock Band in expert guitar, but i cant seem to be able to repeat the deed...
weird :S