NATO alphabet, phone numbers of close friends/family (in case my phone is lost/damaged and I need to call one of them), conversions between Fahrenheit and Celsi

NATO alphabet, phone numbers of close friends/family (in case my phone is lost/damaged and I need to call one of them), conversions between Fahrenheit and Celsius for common temperatures used in biology (both for science communication and also because one time an old freezer had a Fahrenheit scale and I didn't know if -4F was dangerously warm for the reagents stored inside), the 12 times tables (I never learned them as a child due to being transferred at just the wrong time, so it's never been automatic), Vimium shortcuts (disabled now since I know them by heart, but it was a good way to remind myself of features that I wasn't using often at first), Chinese characters.