Today I start back at work after a 4 1/2 month leave of absence. People keep asking me how I feel about this.

“Anxious,” was my answer two weeks ago.

Last week, after coming home from San Diego and still on my BlogHer ’11 high, my answer was a straightforward “ambivalent.”

Now I am neither.

I met with my boss last week and got caught up on things. A few things have changed but even I’m amazed at how much hasn’t.

The problem is, my whole world has changed. I don’t feel at all like the same person I was when I left and if you’ve been reading this blog at all since April you’ll understand why.

So how do I feel about going back to work tomorrow? I feel…lots of things.

I feel ready to get back to “normal” though normal to me is different than it was before.

I feel grateful I’ve had all this extra time with my son and therefore a little sad that I’m losing that.

I feel… Well, honestly, I feel that my job is less central to who I am now.

I work in communications, which is a field I love. I used to come home and spend the evening on Twitter (my other account), chatting to people and following links and devouring information about the latest communications-everything.

I haven’t done that for months, since well before I went on leave.

My last tweet on that account was 59 days ago. Each of the mere handful of tweets I’ve posted in the last few months were either in reply to someone, directed at people I know (family or co-workers), or because my team won an award and, hey, awards must be celebrated. Oh, and one that said, “Yes, I am MIA from Twitter. No, I’m not dead.” (To which I got several “whew” and “I wondered where you were!” responses. Yeah, I used to be fairly active.)

A year ago I couldn’t imagine not throwing my whole self into my job. I loved it, so it wasn’t a chore. But in some ways I think I did it because I felt I needed to. I wanted to keep up with what was happening. I wanted to feel like I was a legitimate member of the communications community. I also had grand ambitions and when I want something I tend to pursue it relentlessly (see also: this whole blogging thing).

So I’m going back to work a different person and a different professional. My days will be spent continuing to work hard at a job that affords me lots of opportunity to learn and be creative. But my nights will be spent here, because that’s the me I want to be.