I’m not familiar beyond the movie tropes (that I now know are misrepresentations).
Are there complications or other serious things that it can lead to?
Are people with narcolepsy generally deep sleepers?
My son, when not on meds, is always very tired, debilitating so. It's life dominating. He can sleep 12 hours, have breakfast, and sleep a few more hours, etc. It's not just a matter of being able to sleep or wanting to sleep, he feels exhausted roughly 20 of 24 hours a day. He would not wake up in 15 mins because a timer went off.
I, on the other hand, am rarely physically tired, even when I've not got a lot of sleep.
So, it may be that you are just more on the tired end of the spectrum. If your tiredness and ability to fall asleep quickly has more than a casual negative effect on your life, it may be something to talk to your doctor about.
HTH.
It can sometimes get worse over time, but I don't know of major complications other than those directly caused by the sleep trouble and AFAIK treatment is entirely symptom based at this point. Medical treatments for sleep disorders are generally not that good (but in some cases better than nothing).
Ideopathic hypersomnia or other hypersomnias might cause your symptoms also (maybe more likely if you are a deep sleeper). Antihistamine use might also make that easier (even second generation antihistamines affect some people that way and some random medications are also antihistamine). Or it could just be luck as you say that you are able to do that :). Unless there is more than what you mention, it sounds like an entirely good thing at this point and hopefully if so it will stay that way. I've heard some people with that ability call it a superpower and as someone who has trouble getting to sleep it certainly sounds like one to me.
The rare diseases summary of narcolepsy notes:
"However, because narcolepsy often goes unrecognized or misdiagnosed, determining its true frequency in the general population is difficult.
The onset of narcolepsy can occur anytime between early childhood and 50 years of age. Two peak time periods have been identified; one around 15 years of age and another around 36 years of age. Some researchers believe that narcolepsy is under-diagnosed in children. Narcolepsy tends to remain a lifelong condition. Although the nature and severity of symptoms experienced by an affected person may varying over time, the disorder is not progressive."
https://rarediseases.org/rare-diseases/narcolepsy/
Edit: As someone mentions above, sleep apnea can also cause this and can be treated.