I get up in the morning and make my way to the kitchen where things seem normal enough. There's my 10-year-old son getting out the Cheerios and my 15-year-old daughter bagging PB&Js for lunch. There's my husband making coffee.

And then: "Aaaaaack!" I scream.

"What are you doing here?" I blurt out to my 19-year-old son.

"I came home to get something," he manages to murmur back.

It's not that he's not welcome.

It's just that I cried as hard as any mother last September when he left for college.

And for what?

In the half year since he's been "gone," I've seen him every weekend and several other days every month. Because he attends college in the small university town where we live, he can bicycle home as needed, often without warning. I walk in the door sometimes and hear him in the basement watching "Scrubs" on TiVo.

"Yo, Mom!" he yells up to me.

My husband and I knew from the get-go we would approach this stage of development like any other. When our children were learning to use a sippy cup, attempting to walk, mastering the potty, we expected forward movement, while watching for setbacks and regression. We expected them to learn to walk. But we held our arms out. Just in case.

Same with college. We don't believe a child packs up his childhood bedroom and never looks back just because somebody says it's time. While some parents follow the lead of more rules-based experts, telling their freshmen they can't come home until Thanksgiving, we prepared to let our son set the pace of separation.

What we forgot to prepare for is how his ambivalence would make us feel like a yo-yo.

What we forgot to prepare for was an impromptu showing at dinner time when we are having arugula salad with chick peas and feta. This is a child who I have seen gag if anything remotely raw or exotic touches the mound of Kraft Mac and Cheese on his plate.

"Hi! Welcome home! Good to see you! Come on in and join us!" I say, overstating my joy while the arugula makes its own statement.

Indeed, Chris takes one look at the table, and his face falls, as if to say, "I see what's going on. You've moved on without me."

Kinda sorta. Yes and no. Maybe. It's true that I don't randomly make his favorite foods anymore. But I have yet to transform his bedroom into an office. And, hey, even though he told us he's not going on spring break with us, I still have a seat in the van reserved for him. With his name on it. Just in case.

The yin and the yang. The forward and the backward. In the door and out. It's no different than potty training, as it turns out, when I had to be the wise mother while he did what he needed to do when he needed to do it.

I called him and tried to explain my position the other day.

"I hope you know when you come home that I really am glad to see you and so that's why I always say, 'Welcome home!' At the same time I don't want you to think you are a stranger in this house, which is what 'Welcome home!' might suggest. I don't want you to feel like a long-lost uncle, or like I'm a desperate, enmeshed mother who can't stand the thought of her son being away from home when what I'm trying to tell you is this is your home forever and always, if you want it to be, and we love you and you belong here if that's what you want, but if it's not what you want, that's just fine, too."

"You OK, Mom?" he said, just like that day when I took him to middle school for the first time.

In the midst of change, some things never do.