The name "Vincent" comes from the Latin verb vincere, which means "to conquer, outlast, defeat." When we first meet Vincent in the Shinra mansion, he is full of remorse and wants nothing to do with Cloud and his party. However, after hearing about Sephiroth, Vincent decides to join them for the purpose of confronting Hojo once again. He can't forgive himself for letting Hojo get away with his human experimentations, and is determined to defeat him.
Vincent has also been asleep for the past 30 years, and has not aged a day since. According to his official stats, he is still 27 years old. As a powerful ageless monster, he will no doubt outlast his enemies and comrades.
The last name Valentine comes from Saint Valentine, a patron saint of love. It has its roots in ancient Roman and Christian tradition. Valentine comes from the Latin word Valentinus, which is derived from valens, which means "to be strong, robust and powerful." Before his execution, St. Valentine is said to have written a farewell note to the jailor's daughter, with the words "from your Valentine," in a famous legend. Thus, the tradition of sending love notes on February 14th has become synonymous with St. Valentine. Vincent's past is shrouded in his tragic love story. Before being killed by Hojo, Vincent had confessed his feelings to Lucrecia, but was rejected.