Stop playing by the numbers

I wasn't trying to but I think I spent the bulk of yesterday realizing how old I have been feeling lately.  It's a funny thing.  I don't know that I have been physically feeling old.  I don't have creaky bones, aches or pains that I can complain about.  I have no health issues, don't have a prescription to my name, and passed every physical exam given me.  I do have the occasional bout of memory loss but that could also be chalked up to all the things going on and not just old age.  But I think the numbers themselves have been playing around in my head.  The years themselves can't be denied and I have been letting that stop me from doing things that I had a notion I should be holding up on.
I have been thinking why should I take on anything new at this point?  I'm old and why keep pursuing anything.
And then at some point yesterday I realized I had been doing that.  Holding up.  Holding back and stopping.  And then I had all these thoughts about what I still want to keep doing.  And I let myself think about it.
It's the worst time weather-wise for me to start training again but really the weather has been great.  I want to start small and start running again.  I need to get those notions that were put into my head out.  The ones that I shouldn't be doing it (at my age).  I'm gonna, hopefully, get myself into some kind of endurance running shape again. 
I want to write, damn it.  If that means I need to register myself into a class where someone sends me an assignment and I get an email back once a week, I'll do it.  This business of writing with no direction isn't working.  I need some feedback that I'm not getting now so an email from a stranger is more than I have now.  At least I will be able to count on that email every week and possibly find other resources by getting involved.
At least it's some kind of plan.  Or at least it's a decision to stop muddling.  I've never been good at slowing down to the rate of what other peoples perceptions want to hold me at.  It's probably because I don't perceive myself the same way.  And I just can't do that.  I'm mean, yeah, I know, I'm old.  The numbers are there to prove it.  And.  So.  I can't keep feeling old just because of the numbers.  I mean, really, if that's the only reason - it doesn't add up.
TT