Thirty?

So, next week is my thirtieth birthday.  I can't quite wrap my head around it- birthdays have always been something fun for me, celebrating with friends and family, but the numbers never really meant much, and now I'm going to be thirty- that's a real grown-up age. 

It's weird, because sometimes I feel really old, and other times I feel really young.  When I'm at work, I feel old- even though I am younger than many of my peers (and older than lots of them), I am further along in many areas of my life (married, homeowner, with kids).  When I'm with my "real-life" friends, I feel really young- so many people I see have more kids than I do, are more involved in community activities, than I am, that it makes me feel really young. 

I don't really know how I'm supposed to feel now- what is thirty supposed to feel like?  Thank G-d I have a good job, a great husband and kids (frustrating as they all may be) but I don't know if this is what it is supposed to feel like.

Or maybe "age ain't nothin' but a number"?