Cooking is a basic life skill and can save you a lot of money. Also, not knowing how to cook is pretty unattractive and is gonna make you appear less appealing for a roommate.
Know I'm not saying everyone has to go to culinary school and become a five star chef to be a good cook. In my opinion, cooking is less of knowing recipes and more so knowing what to do with the recipes. Whenever I cook, I resemble more of a hurricane than a chef, and I really rarely look at the recipe I'm using; I prefer to improvise as I cook, and while that may seem like a disaster waiting to happen, the food I cook almost always ends up tasting delicious.
Cooking is easily one of the most necessary skills you need to thrive in life. You literally need to eat to survive and in this economy, if you want to eat healthily and while not bankrupting yourself, that leaves cooking as the only option.
Cooking also is just such a fun activity. Personally, I've always thought of cooking like alchemy, but instead of ending up with a potion of plus twenty concoctions, you end up with a fire Tuna Steak to munch on.
Knowing how to cook and bake also means giving people gifts, which is quite possibly the easiest thing in the world. Friend's birthday party coming up? Make them a platter of cookies and watch them bite into mini cookie shaped pieces of heaven. Also one of the easiest ways to blow the person your crushing on away is to wow them with your ability to cook up five star meals.
Cooking can also be an incredibly fun activity with friends, just turn on some music, pull out a litany of ingredients and dance-cook the night away. All in all, cooking is just one of the skills that you need to know in life.