Some events are spaced out pretty evenly, regular enough that you're unlikely to forget them but far enough apart that you're usually anticipating it by the time it rolls around again. The holidays are an obvious and very common example.
Of course as you get older everything seems to happen faster and more frequently, so maybe yearly things like the holidays seem a little less special than they did when you were younger. Or maybe not.
But then there are the events that started out uncommon and rare and seemed oh so exciting. But because the response is so positive the sponsors decide they need to do it again. And again. And then more often. Until finally instead of feeling excited by the rare occurrence you feel apathetic, or bored, or even overwhelmed and irritated. What? That thing? Really? AGAIN?
The Humble Bundle sales have definitely moved into that last category for me. I'll still check them out and occasionally pick them up if i see something i want, but i'm definitely not that excited by them anymore and am occasionally even irritated when another email from them pops up.