We go through lots and lots of peanut butter around here. The girls take PB&J most days in their lunchboxes. I like to eat PB&J for breakfast a lot (I did this morning, in fact).
And PB&J is the alternative for children who chose not to eat what was cooked for dinner. I have four children who all have entirely different likes and dislikes when it comes to food. I can't think of any meal that they all like. So, on any given evening, you will most likely find one or more of my children eating PB&J for dinner. It's our way of compromising on my husband's "you'll eat what is served" rule. The kids don't have to eat what they don't like and I don't have to cook something different for each person.