(noun) Word used to label a person who, often in an unfamiliar environment, trusts to his/her extensive knowledge of nostalgia when choosing a topic of conversation.
Origin: According to nostalgic legend, a coconut version of the famous Boost chocolate bar once graced confectionery shelves across the country.
Sometimes shortened to coboo.
See nostalgist and taleggio.
"Hey, guys, does anyone remember Count Duckula?" inquired the coconut boost.