How does it work?

As someone who is new to all of this i have gotten advice that lesion amount is not correlated with disability, so with my age 23, and over 20 lesions, why has mine developed so rapidly and given me so many lesions with minor symtoms only tingling and some people are older than me but with only a few lesions? If i went unmedicated does it mean in 10 years i would have 1000 lesions? I don’t know but this is confusing me and my neuro just said my findings are not unusual and my lesions are not giving me symtoms. Like how is severity of ms measured? Neuro thinks i have remitting.