My third and last child, Kieran, is 20 months old - my favorite age, the age that I'm convinced spawned the saying, "They grow up before you know it."

I love the importance he assigns to every new thing he encounters, things that I have long stopped noticing, much less appreciating. I love his Frankenstein run - he's in too much of a hurry to walk - and his incessant singing, the words revealing themselves more each day. I love the dimpled smile that greets me every morning, reminding me how great it is just to be alive.

Kieran has rocked our world in less desirable ways as well. He was a fussy baby, eating until he spit up, then crying to eat again. It didn't matter whether we waited two or three hours between feeds or fed him on demand. One day, after screaming throughout a store, Kieran upped the volume in the checkout line. Concurrently, a singsong voice said, "I hear a colicky baby," and two 50-ish women appeared.

I was so relieved. I'd always thought the word "colic" merely described fussy babies and secretly (arrogantly) assumed the parents just needed to relax and the baby would follow suit. My provisional mentors explained that some newborns' digestive systems aren't completely developed: "The crying from 4 to 7 each afternoon," they clairvoyantly empathized, "usually stops by 3 months. It's called the fourth trimester."

"My husband carried our daughter and did the Indian dance," one woman said, "Aw-wa-wa-wa."

"Remember when step aerobics was popular?" the other asked. "In the middle of the night, I'd hold the baby and step up and down. ... A colicky baby will get you in shape."

From then on, when Kieran was upset, I'd turn up Eminem (Kieran didn't understand the words) and step up and down the bottom stair. He'd quiet right down.

Whenever my babies/toddlers were difficult, I was grateful when a stranger would say something comforting like "It gets easier" or "It's louder to you than to us." Once I even heard, "You are a wonderful mother." These words, spoken by people I don't even know, often carried me through the day.

Though Kieran's colic passed to reveal a happy baby, he's still very demanding, has a flaming temper and gives new meaning to the term "Mama's boy." Of course, I love being the chosen one, but it has a high cost. Whenever I try to do something - or just enter a peaceful room - I get wailing and pleas of "uppie."

The circumstances didn't make motherhood easier this third time around. We'd assumed - and were on the verge of ensuring - that we weren't having any more children when I became pregnant. I'd already entered the "what-to-do-now-that-my-kids-are-in-school" stage. In addition to my community involvement, I became a CAPS (Creative Arts in the Public/Private Schools) artist and a scientific editor and began to write creative works for publication. Having Kieran felt like starting over, only this time the baby would have to share me with myself.

As most mothers can attest, I am rarely alone. And, with my family, someone is always talking (except my husband). Even when my kids are sleeping - even when I am sleeping - my subconscious is listening, especially for the baby. I once asked my future husband if it was bad to answer the interview question "What are your weaknesses?" with "I can't multitask." Now that's my job description, and it often makes my head ache.

I'm grateful to have been able to stay home with my kids and to have experienced truly and undividedly living for another human being. I greatly respect women who must work through their kids' early years. My current part-time commitments leave me feeling torn and guilty. Kieran embodies the "last time' for everything - the last time I'll sing my baby to sleep, the last time I'll breast-feed, the last time I'll walk in slow-mo while my toddler points at a stop sign and says "S-O-P-P, STOP!" I want to suck every drop out of his baby/toddler-hood, but I also need to continue what I started before his birth. Meanwhile, I want him to feel the same center-of-the-world love that my other kids felt at his age.

Then I think of the mother I once knew whose foster child had never been tucked into bed and my Canadian friend whose kindergarten student was regularly locked outside while his mother was bar-hopping. I remember that I'm a good mother and that, like me, my kids are lucky.

When people say, "It goes by so fast," I usually respond, "If only it weren't all or none." If only we could stretch these early years to double their duration and half their intensity. It's wonderful, but it isn't easy. And we parents shouldn't be so hard on ourselves.