I took down the crib yesterday. My wife, Lisa, and I have had a crib in our home for 23 years. I believed that removing this tangible sign of the near constant obligation to care for infants and toddlers would have little effect on me, but my feelings were surprisingly mixed.Luke, the youngest of our ten children, turned three a month ago. He never climbed out of the crib, so we could have left him in it a while longer. But we decided it was a good time for the transition. One Saturday morning we told Luke we were going to take down the crib and put up his big-boy bed. His siblings talked up this event, and Luke was excited. He happily ran in and out of his room several times while I disassembled the crib. Then I assembled his toddler bed. Luke agreed with his siblings that his new bed was “cool.” Luke will do anything his older brothers do, a trait that is helpful for potty training or learning to pick up after himself.It is not such a good trait, though, when you realize he is probably your last child. Some children develop faster than others, and Luke is one of the quick ones. I know that Lisa has been struggling with this no-more-babies feeling for some time. Having a baby or toddler around has been one of the constants in her adult life. It is part of her identity. It was never a core part of me though, or so I believed. Babies are great, but I have stronger memories of my older children - seeing one of my daughters beat my best 5K time or watching one of my sons hit an over-the-fence home run in middle school. I always felt that watching your kids mature was the best part of the deal. Each milestone was to be briskly approached and passed with satisfaction and excitement.I was not sentimental when I moved a high chair to the basement, or when I took the training wheels off a bicycle. I enjoy watching my children getting stronger - physically, mentally and emotionally.So what was going on here? With a twinge of nostalgia I remembered going to the hardware store when I was in graduate school at Ohio State. We were moving in fall semester, and I had the hand-me-down crib assembled but for one bolt. The missing nut was unusual; I’d never seen one like it before. I can’t describe it even now. But I found one in a bucket of miscellaneous hardware. I was very satisfied with myself. In a small way, I felt that I was providing for my family.I smiled recalling the many times I lowered or raised the mattress because a baby was getting older or a new one was moving in. I remembered the seemingly endless hours of patting a crying baby’s bottom in the middle of the night, or trying to calm a toddler with night terrors. I laughed to myself thinking back at my solution to a problem faced only by a middle-aged dad. My right ankle sometimes pops loudly when I walk, especially if I have not walked on it for a while, like at 3 a.m. This noise has disturbed a newly-patted-to-sleep baby many times. One night I discovered that my ankle wouldn’t pop if I walked out of the room backwards – so that’s what I did from then on.I did not believe my professed preference for handling the older kids was a front, or undue deference to Lisa’s expertise with the babies. But I realized that I’ll never again take a nap in the recliner with a newborn on my shoulder, and I will miss that.