It is a (semi-funny) response, seen a lot on social media like reddit, for example for someone with no chance of surviving a gaming battle due to enemy superior force , originally from 2014 first-person shooter Call of Duty: Advanced Warfare. Quoting know your meme :
"Press F (X) to Pay Respects is an action prompt featured in a quick time event from the 2014 first-person shooter Call of Duty: Advanced Warfare. Upon the release of the game in November 2014, many players of the game mocked the funeral cutscene for its forced element of interactivity that seemed out-of-place at a memorial service."
On most computer applications, F1 is the keyboard shortcut to bring up the help menu. Thus, the phrase "Press F1" is most appropriately given as a reply to anybody who needs help, especially in the psychiatric sense.
<Joe> Oh my god, at lunch today, everybody stopped talking and I said, "Crap, the chat died." I really need to stop wasting time on IRC.
<Phil> Dude, you really need help. Seriously. Press F1.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the USCoast Guard in the area of Southern Florida.
"Base we've got some square groupers floating outside of Miami harbor."
A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.
I had a trucker's tan after driving for 10 straight hours on a sunny day.