Harry Lorayne was an American mnemonist, magician, and author. He was well known for his incredible memory demonstrations and appeared on numerous television shows. His card magic, especially his innovations in card sleights, is widely emulated by amateur and professional magicians.
This is a relatively small book but has a lot of helpful information and tricks to improve memory, including memorizing lists of things, remembering the name of someone you just met, and other helpful real-world things that people tend to forget easily. Some of the tips are gimmicky, but not in a stupid way like some of the things that were hawked on infomercials back in the late 90s. While it is a fairly quick read, it is something that you have to use often to develop the skills within it. So, if you are looking to improve your memory, this is worth reading.