And idiots like me! 
Rules of thumb for portable bottles: keep acetylene upright only. Other than that, if it’s sold by volume, then it’s a gas, so lay the bottle any way you want, it’ll come out gaseous. If it’s sold by weight, it’s liquid, if you want gas stand it upright with the valve at the highest point, if you want the liquid phase turn it upside down with the valve at the lowest point.
Yeah, I hate propane heat (which I have) for exactly this reason. Proper methane (natural gas) is delivered at way lower pressure and does not pool, so it’s a bit safer.
