I could say I learned lots this year through doing my training, but somehow I don't think that's specifically what this question is asking.
I think if I've learned one thing this year is never take something wonderful for granted, because you'll miss it when it's gone.
Throughout all my Spn cons, whenever I've hesitated about going, and worried about the cost, it's always been Mr D who's said, just go - one day the show and the fandom and the cons won't be there any more, and when that time comes, you'll wish you'd made the most of them. And now we are here facing the end of the show, I've learned that he was absolutely 100% right. I'm so, SO glad that I listened to him.