I am a finite group theorist. When I explain to, say, my grandma what it is I do, I will sometimes reference the Rubik’s Cube—one of the more famous places group theory comes up in popular culture.
This created a problem for me, since the inevitable question after referencing the Rubik’s cube is: “How quickly can you solve the Rubik’s Cube?”
My shame was this: I started studying finite group theory in 2003, and I did not know how to solve the Rubik’s Cube. In fact, it was not until my postdoc that I sat down to learn it (maybe 2007). It took me quite a few long nights of listening to Loveline (sadly, with Stryker instead of Adam Carolla) and playing with the Cube to figure it out. But I got it. No more shame.
…until last week. I picked up the Cube last week, and I had forgotten one key step in my solution.
My method of solution is slightly unorthodox (I start by getting the eight corner pieces first, rather than going up in layers), so I wasn’t sure that I could easily find my missing piece online (it is much better to learn it on your own, but I wanted this option as a last resort). Fortunately, I was able to recreate my solution after an hour of study. Better yet, I now understood better what my different algorithms do; I can now solve it faster than before (but nowhere near as fast as this. It isn’t even close).
The lesson learned: it is remarkably easy to forget anything mathematical. Stay in shape by consistent practice.