Kind of off-topic, but "you'll be reminded of each regular expression every time you look at your laptop" reminded me of something:

Does anyone know of a good open-source (or just free to use) flash-cards app? I want to be able to download a bunch of images and create a deck from those images. The front of the card would be an image and the back would be a text description, all created by me. If the decks could be created from a file such as csv or json, it would be great, so I could automate the process of downloading the images and creating the descriptions.

I love regex, but it might be the best counterpoint to the principle of "Comments should explain why code is written the way it is, rather than explaining what the code does." I definitely comment what my regexes are doing if they are at all complicated.