He spins in circles to make himself dizzy, or picks up the hand motions to "Itsy, Bitsy Spider," at day care. He learns to point at the chicken on a page of a book and call it by its name. He figures out how to blow kisses and cover his eyes when he hears the phrase "peek-a-boo."
Unquestionably, the first few years of life are a time of unparalleled learning and discovery.
A quick Google search confirms what seems obvious: At no time does a human brain grow and develop more than in the first three years of life.
It is such an exciting time for the adults who have the pleasure of watching a child grow up. Babies and children are fascinating to watch, and to teach.
As my son gets smarter every day, however, it seems I'm going in the opposite direction.
When my socks don't match, I'm running late or I lose my train of thought, anyone who has been there before is quick with a diagnosis: Motherhood.
I've heard others call it "mama brain." I started hearing the phrase during pregnancy, but later learned the hard way that it doesn't end when the baby is born. In fact, it's going strong with no signs of letting up, making it a little harder to focus on non-baby topics.
As mothers, women, including me, seem to be a little more forgetful, a little more emotional, and, yes, at times, a little less intelligent.
That's why I was surprised to read that a study released in October concluded that the brains of mothers "actually get bigger" in the months after giving birth.
According to a news release from HealthDay News about the study, this is as backward as it sounds. Adult brains don't typically get that much bigger without some major shift or even injury. But sure enough, women in the study showed "significant increases in gray matter volume in various parts of the brain."
All this time I thought my brain must be shrinking, and it was actually growing.
I read a little more into it, and my own observation turned out to be not far off: While new mothers' brains are, indeed, growing, the growth is occurring in certain parts of the brain more associated with "maternal motivation, reward and emotion processing, sensory integration and reasoning and judgment."
So it all begins to add up: Just the motherly parts are growing.
Babies change us in lots of ways -- my body is also certainly extremely different than it once was. It's just a little humorous and maybe oddly comforting to know that there is some science behind what's going on in our heads, as well.
It's a good thing for babies at least, because taking care of little ones takes lots of brain power. It's maybe not so good when it comes to all the other aspects of life.
As they say, though, life goes on. We mothers deal with being more loving, attentive and nurturing and get all the rest done, even if our brains are dedicating a little less energy to all that other stuff.
• Contact Jessica Wiant at email@example.com.