Why do discussions of the origin of democratic government often look back at greece and rome

The reason  is because this is where democracy formed (specifically in Athens, which was part of Ancient Greece), although Greece had a direct democracy as opposed to a representative one.
Both of these nations were among the first ones that try to abolish form of governments that controlled by the kings and tried to create a society where the people held the most power

Up the mula ya know: '(: '(: '(: '(: '(