Perhaps it is my lineage of Oklahoma settlers, but I'm not a big fan of wagons. My mom had a station wagon when I was a wee lad, and I don't remember liking that, either.
But the wagons I am speaking of are of a different sort. The first is the wagon. What used to be a metaphor for sobriety has been hijacked to mean any sort of routine. Workouts, a commitment to daily blog posts, vegetarianism, eliminating "nazi" from your lexicon... you name it. But my ire isn't with the bastardization of the term. Culture does that, and I'm OK with it.
Falling off is akin to falling down.
Don't just lie there -- do something about it! Don't flounder around for support and sympathy -- do something about it! You created the wagon. You decided to crawl upon it. No one pushed you up there. If it's a place you want to be, then be there. If you find yourself constantly slipping off, maybe it's the wrong wagon for you.
And then there are bandwagons. Snaked from the tarnished world of politics, bandwagons have become legion. In fact, they've come to represent any specific wagon referenced above that is shared by multiple individuals. But people don't fall from bandwagons.
If you don't like the direction it's going, get off.
Unless you've got the reigns, you can't steer a bandwagon. The moment it heads someplace you're uncomfortable with, get off. Find another. Or make your own. Or just start walking. All too often, those wagons are filled with sheep. Or maybe that's just how they look to us wolves.