Today my friend Yang came to my house to fix his bike. His back wheel had a puncture a few weeks back. He came to my house to fix his bike last week too. We managed to find the puncture and patched it briefly, though on his way back the patch failed again. Today he came with a new inner tube. We quickly replaced the old tube with the new one. Even ourselves are surprised at how skillful we got after the last experience. This capability of subconscious learning is very impressive. When we were finished with the repair, to our surprise, a new problem emerged – the back wheel became not round after our fix. Could it be a problem with the new inner tube as it indeed looks suspicious? Could it be a problem with the outer tire as it may have been affected when it got the puncture?
Both scientists in training, we immediately proposed models to explain the fact and design methods to validate our models. In the following two hours, various models were constructed and numerous tests were conducted on the back wheel. Sadly, nothing seems to work, and at the end of the day, even I felt bad for the wheel. We finally gave up and decided to ask a bike shop for help. The technician only took five minutes to fix it to a complete perfection, and the five minutes were a profound lesson in humility.