For me cooking and eating is very spontaneous. I also believe this is what separates people who can cook from those who cannot. I can cook because I can mix and match my current appetite, with what I have available in the fridge and figure out something out of that. I know the general idea behind many recipes and cooking techniques but I do not aim to reproduce them to the letter. Nor do I have some kind of meal plan…
You sound like you live alone, or at the very least cook your meals just for you. Because this doesn't seem like it would work at all if you're making meals for multiple people.
About 4 days of the week, I cook only for my wife and me and 3 days/week I cook for friends that we invite; 4-6 per meal from the people that live here. Sometimes it's lazy cooking (nothing microwave or from a package, but a quick asian stir-fry or something), sometimes elaborate; depends on how much time we have (if we have work in the evening).