When did we get so old?

I'm not sure how it happens, or why it seems like it happened all of a sudden, but really, when did we get so old?

When did we get to be old enough that our friends post Facebook profile pictures of their kids (we do it too!), plan birthday parties and play dates, and discuss teething and diaper rash? When did we get to be old enough to discuss house repairs, property taxes and car payments? When did we get to be old enough that we only run into people at weddings and funerals?

Why does it seem like I blinked my eyes and went from 21 to 27? How is it that my youngest brother-in-law, who was a mere teen when I met him, is headed off to college in a few weeks? How is it that babies I held in church are walking and talking? How is it that we [as a peer group] go from our first baby to full-fledged families? [No, I am not pregnant. Thank you.]

It seems that lately life is rushing past my front door. I'm an adult. I'm one of those people I looked up to when I was a teenager. I need to be the example. I'm the mom with a baby on her hip. The wife with baskets full of tomatoes and peaches to can. For my family. For our dinner. I'm the person with the checkbook and the mortgage payment and the property taxes. I'm married to the man who mows the lawn, washes the cars and works a ton of hours to support our family.

When did this happen? When did we get so old? And how didn't I see it coming?