If this was a one-off, perhaps you don't need to do worry about it. However, if situations like these repeat themselves, it might be a good idea to simply observe, for a time, your eating habits and think about what might trigger these hunger attacks.
(What follows are two observations of my own. They might or might not fit your sitation; please judge for yourself.)
Maybe it's how much you eat. The more I eat, the more my body requests food via a feeling of hunger... even in the short term. Apparently it doesn't take my body much time to adapt to a higher level of food supply. This is especially noticeable around Christmas time, when there are regular opportunities for over-eating.
Could have something to do with the stomach being temporarily stretched beyond its normal size... You wouldn't feel hungry again on the same evening because it takes some time until the food you've eaten would be digested, and the stomach empty again. But I'm not sure at all here, I never researched this because once I return to eating normal amounts of food, the hunger pangs usually soon disappear (in the course of a half a wek or so), too.
(Source of information: myself.)
Maybe it's what you eat. You said you ate most of a large pizza, which made me think of carbohydrates, and blood sugar. When I turned 25 years or so, I noticed that eating pasta in the evening, especially a big serving of it, would make me very hungry right afterward. I would know that I was full, but still have a weird, distinct empty feeling in my stomach and aesophagus. When I researched this I learnt (IIRC) that high-carb foods like pasta can trigger a strong insulin response, which can lead to low blood sugar, which triggers that uncomfortable feeling of hunger. (If you regularly experience this, it could mean that you're hypoglycemic. A more protein-rich diet or eating carbohydrates with a low glycemic index (GI) can help stabilize insulin response and blood sugar.)
Your usual dinner (fish and peas) and the pizza you ate seem quite a contrast to me regarding macronutrient constitution (protein vs. carbohydrates&fat) and glycemic index, so perhaps your body was simply not prepared and over-reacted.
(Source of information: A book called Hypoglycemia for Dummies. Despite the terrible title, it's actually a decent source of information.)