An interesting experience recently taught me the difference between seeing and doing.
My youngest daughter was playing with my father's brace. He had worn a leg brace from the time he was nine years old until he died at sixty-six, the lingering result of childhood polio. I kept his last one. Not sure why, but I didn't want to get rid of it. This daughter was barely a year old when my father died, so she doesn't remember him. She was trying it on her leg and trying to walk with it. She began asking me questions about how it worked and how her grandpa had walked. I explained that he walked with a straight leg because the brace had to be kept straight to support his weight, but that he was able to bend it when he sat down. Then I tried to show her how it worked, only I couldn't get it to bend. I knew my dad had bent his leg to sit down, but for the life of me I couldn't figure out how to make the brace bend. I remembered watching my father sit down and he always placed his hand near the back of his knee to make it bend. I had always thought he had just given it a push. That's what it had looked like to me. Then I noticed a tag right around the knee. As I experimented, I discovered that a lever pulled up and released the latch allowing the brace to bend. Easy as pie once I figured it out, but I found it strange that it took me so long to do something myself I had watched my dad do numerous times.
