I may be a little confusing, but I honestly need a good help to make me understand certain things. I like very much to learn theory, but I feel that if I learn it without associating to the real life, it would be like 2 isolated boxes with knowledge, with no interaction. In this post I'm trying to stablish a connecting bridge between Electrical Potential, and how it is useful to us, and how this can connects to our daily knowledge.
I get that we use Earth as a reference point, the origin of our referencial, and I get that we only consider the relative values of potential according to Earth (ground).
My question is, why is ground/Earth used as a reference? Why isn't 1 meter above the ground our reference? Is it because its potential relatively to infinite is -500...(something)Volts, so any overcharge in our devices could simply discharge to the ground? But even considering that this is right, why is it useful? What makes it useful to know that in some point, you got X potential relative to our zero referencial?
Per example, If I say my gravitational potential energy referencial is the floor, I can say that a ball 1m above it has $$m\cdot9.8\cdot1 J$$ of energy that can be converted to kinetic energy. So it's useful to know the velocity before it collides! So, how can we make use of our eletric potential referencial assumption?
Also, when we talk about "neutrals", in our homes(per example), I think that they are used because they complete the circuit between Power Source and ground, but are these "neutrals" the same neutrals that we talk in three-phasic configurations (Triangle, Star) ??