Knife, water (bottle and filter), fire (lighter, flint, small can of gas for emergencies), a warm sweater, change of socks, very small first aid kit (a few pills, needle, antibiotic rolled up in a basic first aid manual), a very small hygiene kit (small amount of concentrated liquid soap, comb, scissors, mirror (has many purposes such as signalling), toothbrush), a small guide for identifying local plants, some emergency rations (couple MREs or power bars), geographic map of the area, .223 rifle, small tent, small tubing (for siphoning gas), rope, small bundle of sturdy twine, toilet paper, collapsible bucket, a few packs of cigarettes (great for making friends or for barter), condoms (multiple purposes, including making friends and barter), fishing hooks, and fishing line. No more than 20 pounds in the pack. Preferably around 15.
A bug-out bag should be ready to go. 20 minutes is too long. And in terms of bugging out, I've always felt that the best survival item one could ever have is a dirtbike. People are bad enough at the best of times, but in the worst of times, there is a good chance that humans will be the most dangerous thing you face. The sooner you can get away from masses of humanity the better. In such a situation, highways are almost guaranteed to be gridlocked. A dirtbike would allow you to travel on the edges or cross country.
I view survival as a pyramid. At the top is your brain. It is the most powerful and useful tool any of us have. Lose your head in a tough situation and none of the gadgets you have will matter. In the middle of the pyramid is knowledge and skills. With the proper knowledge and skills you can make any tool you'd ever need.
And at the bottom are tools. People often focus on these, but in my opinion, they are the least important. The best bug-out bag in the world won't matter a whole lot to someone who's never built a fire before.