Honestly? That it will end.
And also that flamingoes exist.
And also knowing to go to the pet food store instead of the grocery store, and knowing which pet foods are more nutritionally dense than others. A can of puppy food is more nutritionally dense and balanced for activity than a can of SPAM (Protein: 12 vs. 7, Fiber 1 vs. 0, Vitamins: Not There Vs. Oh There You Are!). Canned puppy food and canned puppy milk will keep you going for much longer, be more portable/longer-lasting and won’t have the sugar crash that sodas and candy bars (the usual zombie-apocalypse foods, wtf) will cause. On top of all of this, no one thinks to scavenge from the pet food stores (I have never once seen it in a film, TV show or comic), so you’ll be less likely to run into random people or zombies. Unless there are kitten zombies…