Bread. If I wake up and I'm having a bad day, I buy a fresh-baked loaf of bread and eat it. That's my meal for the day. It's quite fantastic. Whoever invented bread in Mesopotamia or Egypt or wherever deserves the god-kingship they doubtlessly acquired for it.
Fattest greasiest breakfast I can buy nearby. In college I would get the comically american large pancake/proteins + hash brown diner combo before a final and food coma my way through the stress. The place always had a fully decked topping bar so smother that shit in whipped butter and syrup. Calorie bomb helped me focus I think, and I didn't have any money in school so it was also my treat for getting through the quarter.
In a perfect world where I have the energy to cook after a rough day, I'd love homemade chicken stock with carrots, celery, ginger, garlic, potatoes, onion, thyme and Peppers with a little bit of lemon. Pair this with a nice sourdough bread and a glass of lemonade.
In reality: Diet Coke and a bag of chips because I don't have to cook any of those.
The grocery store around the block sells dirt-cheap 2-pc fried chicken + potato meals that I like a lot. I think I used to get the 8-pc fried chicken from Walmart often too...