Random Frustrations

I am always confused at the "re-seal able" packaging that is becoming more and more popular on various items I bring home from the grocery store. Raisins, nuts, bagged cereal, chocolate chips, brown sugar and even 8 oz. chunks of cheese are being packaged in bags that have that "convenient" little "zip" closure at the top. Supposedly these "zippers" allow you to re close the bag with ease, and maintain product freshness. My problem: I can never get the bag open with out some how separating the "zipper" from the plastic package. If I do manage to open it properly- I still sit there for valuable minutes trying to get them aligned to close properly. I still find it much faster to roll down the top of the bag and cinch it with a clothes pin, or just dump whatever it is into a Tupperware container. And that 8 oz cheese chunk? I'd like to see how any one can wedge that cheese back in to the package and zip it up. That one stumps me every time.