Nursery Rhymes

I woke myself up this morning somehow by humming a nursery rhyme. My nursery rhyme was Ba Ba Black Sheep: Ba ba black sheep have you any wool? yes sir yes sir three bags full. One for my master, one for his dame,one for the little boy who lives down the lane. Ba ba black sheep have you any wool? yes sir yes sir three bags full.
Question: When was the last time you sang a nursery rhyme?