Too On/Too Ready
When a person is overly excited about something; being first in line to eat, a date, get drunk, get high, etc... Should only be used before the occasion takes place or at the exact moment it begins. The purpose is to make fun of someone for being overly excited.
Joann was too on/too ready for her rendezvous with Stan that she showed up early. "She's too ready!!" Bill was too on to smoke that blunt, he coonfingered it up! Jim was too on for the concert that he got wasted beforehand and passed out before it even started!