It shouldn't bum you out; it should get you stoked and encourage you to keep trying new things and thinking of new things to try, if anything. Technically you can do whatever you want on a skateboard, the only condition is you just have to actually try it first, see how it works and then figure it out. It keeps hitting me how humans in general tend to be so lazy as far as going through the process of actually materializing their ideas; a lot of them have very brillant thoughts, but besides talking about them they most often never really do shit and it all remains just talk forever. Skateboarding is no exception and the more I grow up, the more I realize how much of a limited and precious window of time skating is in our lives, so we need to exploit that time to its fullest while it lasts because you don't want to turn into that old guy with regrets about tricks they never actually made the effort to materialize, and only ever talked about. Whenever you get a new trick idea, it's quite motivating to realize nobody else is going to do it for you or make it look like the way you picture it, so if you really want to see it you're going to have to get off your ass and do it yourself. Then that's when you love it when shit comes easy. At least that's the way I approach it.