Do you need the alarm to wake you in the morning

When I was a teenager, my mother taught me a trick. When I cannot sleep, I should talk to the parts of my body. It's like saying "arm, sleep now, feet, sleep now...." She said that it is better than counting sheep because you are actually talking to your body parts. And to wake up on my desired time, I also talk to my body before I sleep. Like saying, "hands, sleep now and wake me up at 6am." I have been doing that since I was in high school and it never failed me except when I was sick or I slept very late.