Can symptoms disappear and come back years later?

I’m sure I had worst symtoms when I was a teenager and in my 20s. It seemed to disappear and now 30 years later the day time sleepiness has returned. Is this possible?

I’m not for sure. But from my own experience with this journey. I have only been diagnosed with narcolepsy for almost four years. So, as you gussed it. I’ve only been on medicine for that long as well. But I have had my narcolepsy since about the age of ten. I was home schooled so didn’t have to worry about if I was sleepy and needed a nap. I was able to just go crawl up and sleep. Before I had my kid’s I would go to sleep at 10pm and wake up at 10am. Then take servel naps during the day. When the weather changed or there was a storm coming I slept even more. When I was 20-22 it wasn’t as bad. When I was pregnant I didn’t know about the narcolepsy. It’s the only time I have fallen asleep without warning and standing up.
I think I would have to say it depends on what is going on in your life