Down like six thirty - A phrase popularized in urban hip hop as a term for extreme agreement or participation. It was derived from a visual reference of the face of an analogue clock commonly worn around the neck as part of early hip hop fashion. At 6:30 both hands of the clock point downwards. The phrase is usually accompanied with an exaggerated motion of the speaker thrusting both hands downward to further exaggerate the exclamation.
Fat kids on seesaw's go down and don't come back up. So if u say "your down like a fat kid on a seesaw", u arnt backing out of whatever it is your doing...
Jeff: Hey wanna get drunk?
Bob: I'm down like a fat kid on a see saw!!