Armchair Expert 

Someone who claims to know all the answers to a problem, situation or scenario but has little or no experience or real understanding of it. Usually found on internet forums or writing in the letters section of tabloid newspapers. When faced with educated people who disassemble their argument with facts, they often state they learned their experience at the "University of life".

"If you exceed the speed limit by just 1 mph, you should be banned from driving"

"But you've never driven in your life, you're just an armchair expert"

Armchair Expert by The Welsh Wizard January 11, 2012

Armchair Expert 

Someone who acts like they know the ins and outs of a sport despite never having actually participated in it and having accrued all of their knowledge of the game from watching matches on TV.

Armchair experts typically criticise players way too harshly or referees/umpires for decisions that are very hard to get right, even though most armchair experts would fail to run 100 metres without passing out.

Man 1: "How is he not getting to that ball?!"
Man 2: "There's no way he can possibly get to that, you're such an armchair expert.

Armchair Expert by FF29 September 12, 2020