Electricity is so simple hey? Those electrons what are they? The reason they have all the effects we call electricity is because they have "charge" and that "charge" creates an "electric field." So what exactly is "charge"? What is an "electric field" and how does "charge" create it?
If you want to get mystical about gravity, we really don't know that much about what electricity actually is deep down at the same level either. A bit higher up though, sure. Just like life: we have decent definitions of it and various people have demonstrated that various aspects of it, like cell walls, can be spontaneously formed from collections of particular chemicals. These guys are working from the other direction, looking at how those chemicals could be manufactured by non-living processes.