I'm no expert but I'll weigh in
While there is no certainty from anecdotal reports and I can't speak to any science done on the topic, I think that IMO there are a good number of young people who are being initially very ill go into a remission for some time (the time frame can be decades) but they are still ill--they still have the disease process ongoing.
This has been my experience. And I had symptoms still just not debilitating enough to stop me from living life. Also, it depends on what kind of life one had formerly--if you were an athlete than that would be more difficult to return to than other types of work unless you're a rocket scientist and you experience great mental fatigue.
I think what usually happens (and this is all my supposition) is that as time goes on there is less caution and more likeliness that some major event (either good or bad) will happen that overwhelms your system forcing a crash and possible downward spiral.
Just as a side since I seem to have the floor here
I think some people fall sick initially with very mild symptoms (the initial trigger--which I believe is viral or some other biologic) and then they carry on and later blame the illness on 'stress' factors when they do too much and are overwhelmed causing more severe illness/symptoms.
But I expect you ask because you are young and have not benefited from this 'remission' from being very ill. I so you have my compassion. But you may be fortunate in another way in that, as you probably know, biologic medicine for this disease is now gaining momentum (and we all hope that continues).
Learning to deal with this loss is made more difficult when others cannot see that we've lost anything. I look like a normal person who should be able to do all the things a normal person can (right up to the moment when I push too hard physically or even more mentally) then I either look like a sick person or a very stupid one.
I hope there are treatments that will affect your QoL very soon so that you don't need to worry about waiting for any remission to occur.