How often do you find out that something you've been doing for 20 years of your life, something so natural that you don't even think about it even though you do it four times a day, you've been doing wrong -- and, even more curiously, that a lot of other people have been doing it wrong too?
It happened to me last week. The thing was... tying my shoelaces.
I was browsing the usual blogs and I discovered an instructional video that explained that you can tie your shoelaces well, or poorly, depending on one subtlety in the procedure. The way to tell is to look at the shoelaces – if they are not perpendicular to the direction in which your feet point (i.e. they are slightly crooked), you've been tying them wrong and as a result they are likely to get untied. This is in fact what I've been doing (and subsequently what I've been frustrated by whenever I went running). It turns out that I just need to tie the second loop in a reverse direction to create a loop that strengthens with every step.
More than the actual lesson (and the solution to the problem I've had to solve in poor ways (such as tucking the ends of my shoelaces into my shoes), I was fascinated by the idea that I've had to relearn something so fundamental like tying my shoelaces. I feel like I'm four years old again -- it takes me considerably more time to put on my shoes. I'd like to have more such experiences in life.