When I see mothers with their toddlers, jealousy often consumes me. I pass them in the food store, giggling with a container of Puffs in hand. Sometimes a tantrum is unraveling in a battle for a small toy from the collection beside the school supplies. Stressful or not, I long for the moments they’re living.

When my kids were little, I was envious of every mother I saw. Both strangers at the playground and friends from our Mommy and Me class had something I didn’t. I’d watch as they chased their toddler from the slide to the rock wall to the swings. It was as if physically existing was effortless to them.

Most other moms had a body that functioned. Mine was impaired by a mysterious disease.

When my older son was born in 2011, I’d been living with symptoms like fatigue, weakness and pain for six years. The more I walked or stood, the weaker I became, so our activities were limited to short bursts of standing time. Still, I forced myself to meet friends at the playground and attend story time at the library because I wanted him to experience the world and for us to savor these fleeting years together.

I used to clench my teeth walking up and down the aisles at Wegmans. My legs determined when time was up, whether I’d gathered everything on my list or not. At the playground, I ignored my body’s screams for help by trying to focus on absorbing the preciousness of my son’s youth. But no matter how badly I wanted to chase him as his little legs bolted against the wind, weakness gnawed through my limbs and shook my legs. My body hollered for a seat to rest. I simply couldn’t stand any longer.