I have tbh and say I don't really cook in the true sense of the word. Not sure if that's because I live on my own so don't really have the motivation, however I'm sure plenty single people do cook for themselves!
The fewer to eat the meal, the less worth while the effort and it takes almost the same effort to cook for four, as just one. Worst case is living on ones own and just cooking for your self - the fewer there are at the table, the more expensive the fresh ingredients and the cost of cooking can become. For my usual Sunday dinner I cook a £1 Bisto toad in the hole, make mash, roast, mixed veg and some gravy to go with it. For a change today, I'd bought some sliced roast beef yesterday, added a frozen yorkie pud in goose fat, fresh cauliflower + carrots + broccoli - all bought a couple of weeks ago - chopped and frozen by me and gravy. I intended, out of curiosity, to log how much it cost me in gas to prepare that, but I forgot.
Tomorrow, I'm planning to go to go have a slap up carvery and a pint, in the next town for lunch - much better than our local one, which is just a walk away.