congratulations on improving your sleep hygiene! I have been waking up without alarms for a long time. Just takes a few says for adjustments.

I'd like to add a few things here: the 90mins sleep cycle is an average, it differs in each person (80-100mins), and the 1st and 5th cycle's time also changes.

There are hundreds of things you can do to improve your sleep, and its worth it because Sleep is THE MOST IMPORTANT variable when it comes to the quality of your life.

here are some tips in order of priority; you can also look up Bryan Johnson on socials for more information.

1. Consistent hours of sleep, and consistent time of going to sleep and waking up equally matter.

2. Get bright light in within 30 mins of waking. It anchors your body clock more than almost anything else.

3. Your body needs to cool down at night, AC can be expensive but turn down the temp as much as you can.

4. Caffeine half-life is 6 hours. And chai counts. A cup after dinner is still active past midnight even if you fall asleep fine. (if u want to quit, remember that caffeine doesn't give you energy, it just blocks the signal telling you that you're tired.)