With every birthday, it seems that it gets harder and harder to fall asleep.
But it's not just a myth that falling asleep gets harder as your age-- it's a scientific fact.
Your sleep begins to decline in your late 20s, and by the time you reach your 50s, you spend 50% less time in deep sleep each night than you did when you were younger.
Though there's no way to reverse this process, you can learn more about these changes in your body.
According to a study published in the journal Neuron, "the neurological receptors that pick up the chemicals that signify fatigue decrease over time, leaving you with a sleepy body and a brain that won't shut off to accommodate it.
"It's almost like a radio antenna that's weak," co-author Matthew Walker, a professor of neuroscience and psychology at the University of California, Berkeley, said. "The signal is there, but the antenna just can't pick it up."
Now it's time to invest in a good white noise machine.