If you think your knife is sharp, try cutting plastic with it. If it won't cut plastic, it's not sharp.
I've told this story many times: I used to haul dog food from the Purina plant in Davenport, IA to a grocery warehouse in MI. When you got to the warehouse, and were ready to unload the dock foreman would have you do one of two things, 1. cut the shrink wrap holding the two pallets together with your pocket knife or tear it free and you could restack the product on a pallet. Or 2. borrow, (rent from him) a sharp box cutter to cut the plastic wrap. Price 2-3 dollars or more depending on how many times you showed up with a dull knife. When I showed up the first time he told me the tale and being as I never went anywhere without a sharp knife, I just walked around the stack of DF and said, "Next." We both smiled.
The first CGC I was stationed on the entire deck force was "armed" with Buck 110 folders. I put off buying one for two months until the Chief Bo'son wanted to borrow my knife and I couldn't produce one. He told me, if I didn't have one by noon quarters, I'd be swimming back to port.
We were at Ocean Station November and somehow swimming from there back to Long Beach, CA wasn't too appealing. When I switched to engineering, I added a 4 inch "crescent" wrench to the scabbard. And I carried that combo until I retired in 1989.
Today I carry a small 2" plastic scale folder in my right front pocket because that is all the "weight" I can tolerate in my pocket. And sometimes even that is too much but I still carry it.
Llance