The inflatable swimming pool was filled with water, and the face of my son Zuozuo was filled with joy.

On July 19, after finishing a two-week summer course, I took my son Zuozuo back to our old home in the mountains for a week. At first, he was reluctant to come back with me to our city home. When I told him that we could take out the inflatable pool we bought online last year and soak in it every afternoon, he happily agreed.

As soon as we got home, he started nagging me to bring out the pool. We found it in a cardboard box on the third floor. It was neatly folded. Besides the pool, there was also an inflatable big rubber duck, an inflatable ball, two inflatable tigers on arm bands, and three small inflatable toy ducks to put in the water. We couldn't wait to take all of them downstairs.

After I had inflated the pool and the big rubber duck, I saw Zuozuo's face filled with joy, as if it was lit by a holy light. He came running over, pointing to the patterns on the pool and saying, "Dad, this is an octopus, this is a crab, this is a shark, this is a turtle..." He recited them like he was familiar with them all, seemingly needing my confirmation with a glance. I was amazed at his knowledge of these things - he's not even four years old, how does he already know so much? Seems like today's kids have a lot more channels to receive information, that's why they appear to be so precocious.

In the afternoon, we filled the pool with water. The water warmed by the sun was at just the right temperature. Around 3 p.m., I put him in his swimsuit and swimming cap and let him play in the water. The little guy seemed a bit timid and didn't dare to get in. So I put on my swim trunks and went in with him. At first he wouldn't go in, but then he ended up playing happily in the water and was reluctant to get out.

We had a great time playing in the water. He rode the big rubber duck and suddenly started singing, "Under the bridge in front of the house, a group of ducks is swimming by..." He told me, "Dad, now I'm the duck mom, taking the ducklings out to find something to eat." Children can really immerse themselves in different roles, which helps develop their imagination. I was happy to go along with the story he created and interact with him.

After a long time in the water, Zuozuo's palms and soles started to turn white and wrinkly. I quickly said, "We've played for too long, come on, let's change our clothes." But he still didn't want to leave the pool, telling me again and again, "Five more minutes." I had no choice but to let him stay in the water for another 15 minutes, until a frown appeared on my face, before he finally listened and went to change.

The next day, my niece Dian Dian and my cousin's daughter Xiao Ke, who are one year and half a year older than Zuozuo respectively, also joined in the pool fun. With the company of playmates, the summer dip in the pool became even more enjoyable. The kids would play until their hands and feet were pruned, and I had to urge them to get out several times before they finally agreed.

In the evenings, Zuozuo and I often take a stroll on the country roads. I hold his small hand as we chat and walk. There's a patch of foxtail grass by the road, and I stop to pick a few stems for him. He selects the two largest ones, gripping them in his two hands. I ask him if he's been enjoying his stay in the mountains. He says he likes the pool. He also asks me if the pool can be brought to the city, so he can play in it every day.