“Mindless things” says nothing about ambition. It says something about the reasons for doing anything. It comes out of passion for creating, not because it is the most profitable endeavor, or the most trendy, but because it is the most interesting at the moment. It could be anything, a photograph, a novel or an app. Mindless things is an incubator for ideas. Ideas that may never fully form or reach an audience.
To be honest, most of the things any of us do probably wont really matter in the grand scheme of things and we’re probably not going to change the world in the process. In that perspective, anything could be mindless. There is nothing wrong with trying, just don’t take things too seriously.