Adapted from a recent online discussion.

Question: I am a single mother of two fantastic kids; my son is a college senior and my daughter is a junior in high school. This week, while registering for a college tour for my daughter, it suddenly hit me, and hit me hard, that "someday" is almost here - that day in the distant future when the kids are grown and out of the house.

I find myself crushed by the reality of it. I raised my kids to be independent and (yay!) they are. My son is planning to move to the opposite coast after graduation and my daughter nearly quivers with anticipation when she talks about going away to college. I am so looking forward to seeing what and who they become as adults, but I am at an absolute loss over how to make this transition.

While I have a career, friends, even an S.O. of several years (though that seems to be petering out), my future feels so empty without these two incredible people in it on a daily basis.

Please, help me out here - before I become that old(er) lady in the grocery store who tells the mom with the crying baby and tantruming toddler, "Enjoy it while you can, dear. It goes so fast."

Answer: Hey, don't knock that grocery-store lady. Her reaction is kind, unlike the judgy staring of most - and she brings a ray of love to a moment when you can't think of anything good about parenthood.

They should pick their moments, of course; I recall wanting to kiss some and throat-punch some others. But I digress.

Part of the reason you're so rattled by the prospect of an empty nest is the clean and clear sense of purpose child-rearing hands you. When you're faced with a tough decision of any kind, minor or consequential, you have them to ground you, direct you, and validate your purpose: "It'll be better for Child if I do X," so you do X. Decision made, sense of self-worth affirmed.

Soon, without this clear path, you'll have to come up with answers the hard way. What do you want? What is right for the sake of being right, instead of right for The Children?

The easy answer is to have a different purpose, one that feeds the same part of you that was so well nourished by motherhood.

The hard answer is figuring out what that is. Don't be afraid to take your time, try on some ideas, and reacquaint yourself with traits and priorities you set aside long ago to be a good parent. With so much of you focused on others, it's almost impossible for there not to be something you sacrificed. Trust yourself and let it come to you.

Chat with Carolyn Hax online at noon Fridays at www.washingtonpost.com.