o3' Jetta Starting Problem

I get into my car and no clock, no milage, basically nothing. I try to turn over my car nothing. The lights were'nt on or anything left running. I'm on lunch break so I just decide to sit in my dead car and eat, meanwhile the clock and milage reappear from no where and start going bonkers. I try to turn it over, nothing. They stop going bonkers right when I attempt to start.Then it happens again, I let it go this time to see what happens, the clock and milage resets themselves and my cd comes out. I turn it over, it starts with no hesitation. Any thoughts?

check the negative battery cable connection and make sure its tight.