As a boy of about 7 or 8, my mom wanted me to learn how to swim, so signed me up for a swimming class at the Y. I had several classes over many weeks with a number of other similarly-aged youngsters. I learned some of the basics, but hadn't fully grasped how to swim by the time we had our last day of class.
On that fateful day, parents were allowed to come and see what their children had learned (my mom came to see me on this day). The better swimmers did laps near the middle of the pool while I, being just a novice, hung close to the side of the pool so that I could easily grab the sidebar for support. We had at least a couple instructors who were in the pool with us at all times.
On one lap, I got too far away from the side of the pool and felt like I was about to drown. I desperately tried to tread water, but was starting to panic. I looked up at my mom. She appeared to be looking elsewhere. None of the instructors was looking my way. With water in my mouth, I couldn't yell or scream. After what seemed like an eternity, one of the instructors finally came to my aid and said she was sorry she had forgotten me.
Several years later, I had swimming class in junior high, but still didn't fully learn how to swim. To this day, I still don't.