Peeling off tab seals can be a challenge. This might apply to some containers, but have you ever tried doing it with a gallon of milk?
“These Are the Worst. How to open one of these.
Step 1: Pull on tab.
Step 2: accidentally rip tab off without breaking the seal.
Step 3: Plunge your finger in seal with rage.”
Image courtesy of http://cheezburger.com/6980873984.