10 Things Everyone Needs to Be Able to Cook

There are some basics that everyone should be able to cook.  You might end up with a few staples and no store access for weeks.  You might end up out in the wilderness and need to put together a meal with very meager ingredients.  You might be put on the spot at a family gathering and need to whip up something amazing with what you have in the fridge.  These are the basics that everyone should practice making until they are reasonably competent at it:

1. Bread.  It's the staff of life and with a few ingredients you can make a staple food to keep yourself full no matter your circumstances.
2. Soup.  This is a basic that can stretch a few ingredients into a filling meal (ditto for chili).
3. A grain.  Depending on where you are from, a basic grain like oats (oatmeal), corn (grits), wheat (porridge), or rice (congee) is usually a simple-to-make breakfast staple.
4. Salad dressing.  From basic (oil and vinegar) to fancy (seed based dressing with a dozen ingredients), being able to make a dressing that can be used on salads, over vegetables, or on bread can dramatically expand your cooking repertoire.
5. Meat.  These days you can buy pre-cooked meat from the deli section of your grocery store and never learn how to make it yourself.  In a survival scenario, you need to know the basics of meat and fish cooking so if someone tosses you a skinned squirrel or side of pork, you would know how to prepare it so that it remains edible, and preferably, tasty.
6. Vegetables.  Some people hate vegetables, most likely because they were given vegetables to eat by someone who had no idea how to actually cook them.  I've never met a vegetable I didn't like, as long as it was cooked properly (ie: not boiled to mush or scorched).  Bonus points if you learn how to find and cook wild edibles.
7. A dessert.  Something to round out the meal and give people something to look forward to after dinner.  Deserts can be simple (melt chocolate chips and peanut butter together then add oats to make no-bake cookies) to elaborate (baked Alaska).
8. Foreign foods.  Indian, Asian, Mediterranean, even African food is usually based on basics (a grain and spices) yet these simple foods can be complete, filling, and enjoyable meals with a bit of cooking skill.
9. Foods to feed a crowd.  There are some tricks to cooking for 50 to 100 people.  Simple is good of course, and food that is able to be cooked in bulk is also good (you don't want to make deviled eggs for 100 people).  Spaghetti, sandwiches, pizza, a crawfish boil...you never know when you might end up cooking for a hundred first responders during a disaster.
10. Coffee.  Everyone should know how to brew a good cup of coffee.  Even if you don't drink coffee, you will probably end up making it for others sometime in your life.  Besides using a basic coffee maker or fancy espresso maker, you should also learn how to make it with a French press as well as boiled over a camp fire.