Nope, definitely not crazy and certainly not alone.
"symptom watching" is something I bet the vast majority of us do: it's only to be expected if you are told you have a condition which is likely to get worse. It can actually be really useful when consulting doctors -- for instance, imagine telling a doctor you think you're getting worse and he/she asks why you think that; you can either say, "Hmmm...dunno really", or you can say, "well I do X three times a day, but now I can't do it any more".
The only thing wrong about it is that, yet again, we are all left to find our own way of doing things without any help -- perhaps it would be useful if, when we're diagnosed, we were given a chart of movements or exercises to do, so that we could regularly keep score and report back any changes, (although that would be a pretty demoralising diary to keep). I can't remember who it was, but somebody once posted here that they took an annual holiday to a cabin in the woods. Every year, they monitored how many logs they could chop, steps they could climb etc, and keep tally that way.
Think of it as "patient monitoring", and it doesn't seem half so crazy!