I replied to this LJ MS community post with the following and wanted to record it here for posterity. It may not be my best ever piece of prose, but here it is anyway:
I went through Sixth Form and University (BSc and then MSc) with MS but undiagnosed. It might have actually been easier to be able to tell family, teachers, doctors, friends and other students that there was a reason for me being ill all of the time.
I thought I was a mad, neurotic hypochondriac and so I am sure that most of them did as well! I thought that everyone felt like this (because of repeatedly being told that, "everyone gets a bit dizzy/tired/etc.) and that I was just a useless wimp that could not cope with what everyone else could cope with. Cue much depression and counselling.
As it was, I did not get diagnosed until I was 30 and had been out in the working world for ten years (so, ditto the first paragraph also for clients, co-workers and bosses!). I would sleep so that I could get up and go to work so that I could pay for a place to live to come home and sleep all evening/night/weekend. Heh.
I am SO glad to have a diagnosis, even if it IS something incurable.
We think that my first symptoms, in hindsight, were when I was nine and thirteen although there are things that happened even younger than that that may have been the MonSter's fault. If only I had known then and had been able to start on Copaxone back then (zero major relapses since starting!) I am sure that I would not have become the messed up and depressed 40-year-old that I am now! Back then, though, medical 'knowledge' said that kids could not have MS and that MS could not cause pain (a theory that some doctors over here in the UK still expound) and so it taking until I was thirty is less surprising than just plain sad.
I am glad for you that you are able to give a 'real' reason for any symptoms to the people around you whilst, of course, wishing that you did not need to and that you did not have MS. *hugs*