Sleeping by myself

Last night is the 3rd night in a row that I go to sleep by myself. I used to have Dad accompany with me to drink milk in bed then slowly fall asleep. As I will be 2 years old in few days, Dad started to train me sleep by myself. He still accompany with me to drink milk in bed but then he will leave the room for 10 minutes and let me try to sleep. Though it is not smooth that every time I can do so, I usually can make it when Dad become serious half hour later.