I have noticed that the food I make myself just seems to taste better. I know this is a very selfish thing to say. In fact, this kind of selfishness is quite common. We humans overvalue the things we make for ourselves. For example, that Ikea furniture that we put together. It's not the greatest furniture ever but assembling it adds to its value for us.
I was reading about this in Dan Ariely's book
The Upside of Irrationality
. "Pride of creation and ownership runs deep in human beings." Ariely says that creating food is a good example of this. Even semi-homemade items taste better to us: steps such as adding some herbs to a bottled pasta sauce, mixing curry paste with chicken pieces, or adding eggs to a cake mix. These at-home adjustments give us a feeling of agency over our food, and hence the food tastes better to us.
But often homemade really does taste better, right? It's not just psychology that fresh from the oven muffins taste better than store bought. Adding fresh chopped parsley to a bottled sauce does, indeed, make it taste more fresh. (Although there is a line beyond which I don't think this is true; adding eggs to a cake mix may not actually taste better than a not-at-all homemade factory cake.)