Hipstorian
A pontificating, preening and obtuse human person who has an emotional opinion on past events based on nothing but conjecture and complaint or a total misrepresentation or misunderstanding of facts.
An hipstorian at Starbucks just tried to explain to another guest how he was a huge fan of the band Mumford and Sons years prior to the “Sons” being born and joining their father’s group and that he owns all of Mumford’s OG work on cassette tape.