Going on about 10 years now. It took me about a year as a solo pilot in SVGA AW to get a consistant, positive K/D. I think that's why the steamroller, war-winning style of "play" is so popular. Your ego can take quite a beating, night after night, until you start making fewer mistakes.
Learning the art of SA is probably more important than ACM, IMO. At least it was for me.
Charon