With the Train

Seth has loved this train since his Grandma and Grandpa got it for him for his birthday. He always had fun pushing it - but his legs would go so fast he would fall right over. So we would have to either hold one of his hands or hold the train so it wouldn't go so fast. Yesterday Seth figured out how to do it all on his own. He was walking back and forth in the apartment and down the hallway pushing the train and laughing so hard. Could walking on his own be that far behind?