St. Nicholas as legend has it was a very caring, compassionate, and giving man. He was orphaned at a very young age when his parents contracted a deadly illness. They had a significant amount of wealth in which Nicholas inherited. As he got older he learned of God and Jesus. Particularly Matthew 19:21 Jesus answered, "If you want to be perfect, go, sell your possessions and give to the poor, and you will have treasure in heaven. Then come, follow me.
One of the first things that Nicholas is noted for is help the three poor maidens. Summing what he did up, Nicholas secretly gave each of the young maidens a bag of gold by throwing it in the window. One of the bags landed in the maidens stocking, which is where contemporaries get the Christmas Stockings. He did this for all three girls and with the last one, their father caught him and thanked him.
Just this story of Nicholas shows his compassion and his desire to not bring attention to himself. He wanted God to get the glory instead of himself.