Yesterday it was raining when I had to walk the kids home from day care. It wasn't raining hard enough to call for Amy to come pick us up, but it was raining hard enough that I needed to hold an umbrella over myself and Jada (Aaron was safely tucked underneath a clear tarp that goes over the front half of the stroller). Since I had to push 80 pounds of flesh and metal with one hand, I found myself constantly lurching to the left if the street was slanted downward to the left, and to the right if the street was slanted downward to the right. At one point, I even stopped to inspect the tires of the stroller, to see if I didn't have an alignment problem.
The next morning, with no rain and therefore both hands available, I experienced no such problem pushing the kids to day care. It occurred to me that what allowed me to navigate the stroller so smoothly with two hands was that every so often I would almost imperceptibly adjust my steering in one direction or the other to keep everything going straight. It's like when you drive a car - even when you're going on a straight road, your car very rarely is going perfectly straight (as if you could let go of the steering wheel), requiring instead occasional adjustments that are so small as to not register to the naked eye (or even to yourself).
It also occurred to me that this is an apt analogy to parenting: two adults, working separately but really in tandem, making small and periodic adjustments to avoid lurching to the left and right and to keep things going straight. When one pushes too hard, the other has to counterbalance; as is the case when one lets go. Please understand: I am neither scolding nor sainting single parents, I am speaking solely to couples who parent together. And for those of us who push our kids forward in the stroller of life, my insight is that even when the road is straight, it takes subtle adjustments from two sides to keep things going straight; and when the road is tilted to the left or right, those adjustments must become more forceful and deliberate.
This might not be at all insightful to you, but it was a helpful thought for me. And it was more than I expected to gain from one walk home in the rain with my kids.