Too Pooped to Pop

I can remember my Mom saying "I'm too pooped to pop." so often when I was just a kid at home... And I always wondered what she meant by that exactly. I mean, really?

How does one pop?

Isn't that a kind of low volatile word for explode?

When you pop a firecracker, does it not explode?

But today.... I really think I understand what she might have meant by that saying... I worked my butt off last night moving the same pallets of freight around that's been "stuffing" the same back room of the same Walmart Store for weeks, just so I could stuff more of the same kind of freight in the same space to the point where you couldn't possibly put another pallet without blocking any and all possible movement through the space..... and when I got home...... I was too pooped to pop up on my feet and do anything without fear of falling to sleep standing up..... tooooo pooooppped to pop!