I have been studying Capacitors for the past year now and the one thing I don't understand is how a charge is stored on the capacitor. Essentially, a circuit with a capacitor is an incomplete circuit right?

So why do the electrons start to gather up on one of the plates. Its like they are tricked into thinking its a complete circuit and get trapped once they realise it isn't! What is this sorcery!

What is happening to make the electrons do that and if it simply is electrons moving and then turning back or getting stuck, would a switch have the same effect? (Assuming the switch is open).

Hopefully someone can finally fill the major gap in my knowledge because everything else I read doesn't explain this.