Why when I am asleep am I unwakeable?

This is not due to drugs or drink, I’ve been this way since childhood at the least. When I fall asleep you can punch me, throw water on me, throw me off the bed, and I will still likely sleep til morning.

I’ve always just known this as a personal quirk but it is kind of odd, my wife tried to wake me because of a house fire in the area and…nope she told me about it in the morning and was upset I am basically in a coma when asleep.

Basically just once I fall asleep no external force is going to wake me short of I guess picking me up and throwing me against a wall. Is this odd, common?

When I was 8 years old I rolled off the top bunk of a bunk bed and fell with such a crash to the floor that it woke up my parents from a sound sleep. When they came into my room they found me sound asleep on the floor. They just picked me up and put me back into bed. I don’t remember it happening.

I used to be a hard sleeper like you, but the older I got the lighter my sleep has gotten. In fact I now wake up numerous times during the night for no apparent reason. Apparently I grew out of it. I don’t think it’s all that uncommon.

Are there specific noises or events that will wake you easily though? Something that signifies morning like the sun, your alarm, the footsteps of the pedestrian that walks by outside at every day at 5:30?

Mrs. Fluffy goes to bed much later than me and is often up in the middle of the night doing paperwork (yes, she’s weird). She is constantly amused by my ability to sleep through lights turned on and off, loud noises, being pushed over to my side of the bed. Yet I wake up instantly to my phone alarm, which is a gently melody that she usually cant even hear, going off in my study down the hall.

There is certainly evolutionary and practical advantages to being woken by noises that may indicate danger or opportunity, but being able to sleep through unimportant disturbances is also advantageous. I’ve known plenty of light sleepers that would love to have the ability to sleep through all the minor crap that wakes them up.