I am sure there would be lots of people here who would experience this one too - I can go from feeling passably 'normal' to feeling like a complete basket case as a single day progresses. In the morning, I might be a bit slower than my recollection of what 'normal' was (although it has been so long I can't be sure if that is just wishful thinking)....but by the time three or four o'clock comes around, MS fatigue has bitten me and I am not much good for anything. Some days are certainly better than others, and the temperature has a lot to do with that as well.
For me, lots of stuff comes and goes, day-to-day. It is from residual stuff not relapses though. When I have had an attack, I have pretty much been left with residual symptoms (though much less-so......like a shadow) forever.
Multiple Sclerosis Dx 2001 Craniotomy to clip brain aneurysm 2004. ITP 1993.