“I want to go back to the Islands,” my four-year old looked up with me with his blue eyes rimmed with golden flecks. He asked it with a hint of expectation, as if going to the Caribbean was as easy to pull off as a jaunt to the park.I brushed his golden locks off his forehead with my fingers, as I stumbled through an explanation of how special our sailing trip had been.When we spent a month on a sailboat, he’d tell me, “I want to go home.” He missed hanging out with guys and would complain, “These girls are giving me a big, hard time.”Once when the boat got so heeled over that we stared at the sea passing within a few inches reach, he screamed, “I don’t want to drown.”Hearing his high-pitch scream undid me that afternoon. I worried I’d pushed his comfort zone too far. Instead of exposing him to an incredible learning opportunity, I’d terrified him.I wondered: Where does one draw the line when challenging their kid to get outside, pushing them to try new sports and new experiences? I asked myself whether a month was too long for my son to be out of his routine, how many hours was too long to sail each day. One day I’d think I’d made a bad decision, and the next something on the boat sparked his interest. He’d ask how the engine worked or poke his head in while we were doing the morning engine check, asking us about each part. My son asked how the boat turned and how the anchor held us in place.Getting comfortable on the boat wasn’t immediate. One hour he’d be full of questions and ideas, I could see the excitement in his eyes. The next he’d be complaining that didn’t want to go sailing. Later on he’d pee off the side of the boat and I’d see him shine with pride that he felt comfortable doing things on his own in a new environment.By the end of the month, he’d be the first to point out a surfacing turtle or a swooping pelican. He knew how to turn the engine on and off, and could even steer the dinghy on his own. At four, he could explain how the windlass worked to lower the anchor and what we needed to do in order to sail upwind. I glimpsed the person he’d become. He would want to help out and get right in the mix, learning. He would have an easy relationship with his own skin and be most comfortable outside.If I’d balked when my son was the uncomfortable, he wouldn’t have struggled, faced with opportunities to grow. The big leaps in his development sometimes happened suddenly, after days of struggling with his attitude. I realized that sometimes to know where the line is between what our kids can and can’t take on requires that parents cross them. Boundaries aren’t linear nor do they stay constant.