I don't know why I don't play.

[SeaWyrm]

Brains are weird.

I think actually stepping away for too long makes it worse, despite what everyone thinks. You get in the habit of not playing and then you don't want to anymore even when you want to.
Usually for me at least, the thing that triggers getting back into things is for me to actually play them for some reason, and THEN I start wanting to play more.
And don't talk about how you're about to come back and play again, or about how you really should come back and play again, or anything along those lines. It does a weird thing where it makes it less likely to happen. Especially if you say "should". Nobody does things they "should" do. Even if you think you "should" play and then you play, you'll have played because you should have, not because you wanted to, and your brain won't think you like the game after all.

(Or maybe everything I just said isn't true at all and I'm full of it. YMMV.)

[Wats]

No, I think that's probably pretty accurate for some people, myself included. Procrastinating from doing something you enjoy is weird.

In my case, I'll take breaks, sometimes for a week, but beyond that I'll find myself making excuses for not playing. And thus begins the procrastination. So I'll hop onto Mumble, telling myself "I'm not actually here to play a game; I just want to see what's new and chat." Then someone asks me for a game. And I say "Sure!" And that weird part of my brain goes "Dammit, I didn't want to do thi--PREPARE FOR DESCENT--Oh right, this is fun! I'M HAVING FUN!"

In each match I usually make sure to catch at least one smart missile directly into that weird part of my brain. Seems to help.