system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: I open a big bag of chips, Family sized. I take my portion, and also fill 3 zip lock baggies with those freshly opened chips. TWO DAYS LATER the chips I put in the zip locked bags are STALE. 2 WEEKS later, the chips in the original bag are not stale.

I thought I would be saving money, saving the chips in fresh zip locked bags, but no. Stale as Hell. I am old. I don't do it anymore, I'm just wondering why, when I leave the family sized bag folded over/barely closed, WHY do they still taste fresh, and my "freshly" sealed goes bad within 2-3 days? Cheers!
gpt
Bags of chips are not full of air, they are full of nitrogen (I think) or some other chemical mix that keeps things fresh and reduces moisture and bacterial growth. As soon as you open the bag this dissipates.