Psychology explains why your brain wakes you just before your alarm

Your brain anticipates waking by adjusting hormones and body temperature. This internal body clock, known as the circadian rhythm, regulates daily cycles. Cortisol levels rise naturally, preparing you for the upcoming day's demands. Consistent sleep schedules strengthen this internal timing mechanism significantly. Expectation also plays a role in training your brain for anticipated awakenings.

Raccontata daeconomictimes.indiatimes.com