You've unlocked a core memory for me. Think I was about 4~5 yo, we were on a family trip to a resort. I was sitting on a noodle bent in a U-shape in the pool and had waded towards the middle, still next to the wall though because I didn't know how to swim. Although my mom always had me wear the life vest, this one time i didn't as I thought the noodle was all I needed and also didn't want to look like a baby in front of my older cousins.

Before I even realized, the noodle shot out from under my butt and I just silently sunk. None of that flailing and splashing that they do on TV happens. I also clearly recall just looking up at the super-close surface, gulping down mouthfuls of water in an attempt to breathe, thinking this was the end. And I think the worst part was feeling the wall with my hands but being unable to grab the ledge because it was too high (I was underwater, my arms were short, etc).

My uncle was sitting literally feets away from me, he said he was watching, it just looked like I was playing- bobbing my head in and out. Then he realized I wasn't coming up and jumped in to save me. My parents almost quite literally threw me into ymca swim classes as soon as we got back home.

If I ever have kids, swim lessons will be a must.