That's a good one. When I moved from Germany to the US in '92 I looked down on pies - nothing like a good German Apfelkuchen. Fast forward 20+ years and I'm slightly obsessed with making a good apple pie. Lots of variables and due to fluctuations in the exact makeup of the ingredients it's a new challenge every single time.
I came here to say I recently took the time to really understand the Lucas Kanade algorithm in depth but I'm going to join the apple pie bandwagon instead.