Today is Pancake Day in the UK otherwise known as Shrove Tuesday, which is the day before Ash Wednesday and therefore the day before Lent begins. In other parts of the world—for example, in historically Catholic and French-speaking parts of the US and elsewhere—this day is called Mardi Gras.
The reason that pancakes are traditionally eaten is that the 40 days of Lent form a period of fasting, during which only the plainest foodstuffs may be eaten. Therefore, rich ingredients such as eggs, milk, sugar and flour are eaten immediately prior to the commencement of the fast. Pancakes and doughnuts were a great way of using up these things prior to fasting. The word shrove is a past tense of the English verb "shrive," which means to confess and therefore Shrove Tuesday gets its name from the shriving (confession) that took place immediately before Lent.
All over the UK people will be eating pancakes to mark this day before giving up something for Lent. I like my pancakes with lemon juice and sugar and I promise faithfully that I will then give them up for Lent. They are just too yummy!