Since childhood I had heard people say that "everything changes when you have children." I never knew precisely what they meant, but I didn't fail to note the ominous tone in their voices. When I contemplated marrying a man with custody of his two children, I remembered the warnings. I couldn't quite, however, absorb the import of that caution about "everything being different."

Four years later, I can confirm everything does change. Every aspect of a day, from food to friends, is different.

Food, for example, was formerly looked on in two ways. It was something needed to survive, to work late on without getting hungry or distracted. It was also something in which to luxuriate, as in elaborately prepared dinners. Food is now the chief organizer of my day.

I have learned that children aren't impressed with gourmet specialties. They tend to the plain and hearty. They view food, like everything else, as a medium of expression. When they were younger, food was considered something to sit on, throw, smear, crumble and otherwise interact with in every way but consuming. (To this day, our daughter still cunningly scatters fish to the far edges of her plate with such artistry as to make what has not been troubled appear almost eaten.) They like to name food, too. Mozart Casserole isn't called that because of their early exposure to classical music. It's called that because its black olives remind the kids of our departed cat.

Shelter, like food, look different to me now. My grosser perceptions of it have been considerably refined. I am fine-tuned to detecting whether a home's potential playroom is far enough from the living room to prevent "Give that to me!" and "I did not!" from reaching the latter.

Shelter-assessment means remembering the life of a piece of furniture is significantly determined by how much bouncing it can take and how many glasses of spilled milk it can resist. It means not getting too attached to objects -- a rocker I'd had for eight years survived three weeks after being placed in our playroom.

If shelter had been my anonymous backdrop, clothes I had looked upon as costumes -- expressers of mood, enhancers of mood. Now my own clothes must be as serviceable as battle fatigues. And the crucial test of durability is mercilessly applied in selection of children's clothing and shoes.

My former method of relating to clothes which developed tears, holes, undone hems, buttons off and all the other frailties of cloth was to cavalierly put them into retirement, or even discard them. Now I have a mending pile.

It had never occurred to me how many clothes there would be to wash. More people mean more clothes, sure, but I hadn't considered frequency. After such a sedentary life style, I didn't think about a child's item of clothing seldom being worn more than once without washing.

The obvious fact of growth I had ignored, too. My concept of growth was the fluctuation in my dress and slacks size.

Shopping had to be the most hellish of the new experiences. I had thought a store was just an assemblage of buyable items arranged in a manner conducive to selection. What I now know is that a store has racks to hide under, aisles and corners to run around in, an abundance of places to get lost in, as well as my number of supremely breakable goods. Furthermore, it is structured mostly to adult dimensions, so that a few steps away means loss of child surveillance.

I was never good at shopping. I could end up with an orange and purple velour blouse ("handwash only"), or nothing at all, because I am confused by a large selection of anything. It took an incredible power of concentration for me to decide when the crucial jump from 6x (the outer limit of toddlers) to 7 (the bottom limit of girls and boys) had been reached.

My capacity to concentrate, however, actually may have increased. I figure anyone who can read Joseph Conrad with a 60-pound dog on her lap, the same few notes of the "Star Wars" theme being whistled for the 64th time, and 10 Little Indians for background from a beginning flautist, is one hell of a reader.

My friends also have been sorted out. I have learned that there are people who like kids, people who can stand them, and people who decidedly don't like them. And while I've hardly made child-liking a criterion for friendship, it does show me new dimensions of people, wherever they fall on the spectrum. The childless friends are the pathologists and radiologists of life. The ones with children are the medics, the frontline purveyors of, among other things, rescue.

When responsible only for me, "health care" meant remembering I have teeth and wear contact lenses. Now I daily decide how significant are hurts. I have called upon a hitherto untapped store of home remedies -- things which my own mother did which I hadn't thought of for years. I have remembered Castoria, Calamine lotion, nose drops, Musterole, cherry cough syrup and the comfort to a child when a parent appears to know what they're doing.

Someone who truly knows what they're doing would, it seems, have though of baby sitters. I have developed an intense interest in neighborhood teen-agers, childless couples who might welcome an occasional weekend at parenting, potentially grandparently types and all other species of baby sitter. For baby sitters are key . This is an example of the kind of interest which is immediate and overriding with children, and totally irrelevant to the childless. It is incredible to me now to think how many years I went without once considering the importance of baby sitters.

Those who'd said "everything changes when you have children" hadn't mentioned the pivotal role of baby sitters. They also hadn't mentioned sex. It's not true that sexual interest declines with the presence of children -- it just has fewer opportunities for expression. This is important. Very. Afternoon delight and lazy, lustful Sunday mornings are far fewer. Tiredness is also important to consider. Children tire people out.

Which brings me to sleep. I used to take naps and sleep late on weekends. I never worried about how late I stayed up, because I knew I could catch up. None of the above is very often possible now. On the other hand, Bedtime, like Mealtime, now means something. Bedtime means the time of night when the children go to bed.

And so on . . . learning to think of empty grocery containers for their potential arts and crafts uses, driving with chaos in the back seat, getting out tangles, Halloween costumes and P-TA. "Everything" certainly does change with children.

I live a day differently than I used to. But not just because there are more and different demands on me. A day is also funnier, more immediate. The demands are random and unexpected, which calls for more use of my resources than when my life was compartmentalized into work and social life.

I am asked by my children whether I believe in God -- asked by people who really care what I think. I am asked to explain windmills, menstruation and long division. I get to relive parts of growing up, which helps remind me what I like and dislike about myself, and how I got to be me. There is less room for posturing, more room for vulnerability.

I get a chance to see myself in the eyes of those who know me best, and are both unmercifully honest and kind. And there is more opportunity for pure play.

Of course I'm not this sanguinewhen I've been interrupted for the 32nd time, or when I get waked early on a Sunday morning. And my final verdict, if there ever can be one, won't be in for years. My interim verdict is that the "everything" which changes includes me, which can stand some changing.

Just ask my kids.