Tomorrow is Ash Wednesday. It is not uncommon to find a modest amount of celebration on the day before the first day of Lent. This is done as a sort of last gasp; signifying that from which we are going to deny ourselves, in the forty days to follow. Here, we read Father Saunders' explanation of the traditional meaning of Shrove Tuesday.
"Shrove Tuesday is the last day of what traditionally was called 'Shrovetide,' the week preceding the beginning of Lent. The word itself, Shrovetide, is the English equivalent for 'Carnival,' which is derived from the Latin words carnem levare, meaning 'to take away the flesh.' (Note that in Germany, this period is called 'Fasching,' and in parts of the United States, particularly Louisiana, 'Mardi Gras.') While this was seen as the last chance for merriment, and, unfortunately in some places, has resulted in excessive pleasure, Shrovetide was the time to cast off things of the flesh and to prepare spiritually for Lent.
Actually, the English term provides the best meaning for this period. 'To shrive' meant to hear confessions. In the Anglo-Saxon 'Ecclesiastical Institutes,' recorded by Theodulphus and translated by Abbot Aelfric about AD 1000, Shrovetide was described as follows: 'In the week immediately before Lent everyone shall go to his confessor and confess his deeds and the confessor shall so shrive him as he then may hear by his deeds what he is to do in the way of penance.' To highlight the point and motivate the people, special plays or masques were performed which portrayed the passion of our Lord or final judgment. Clearly, this Shrovetide preparation for Lent included the confessing of sin and the reception of absolution; as such, Lent then would become a time for penance and renewal of faith."

I had never heard this explanation before, Paul. Very informative. Thanks so much for the link. Something new to teach my teenagers!