Earlier quoted context omitted.
In one of the call of duty games, you attend a funeral and when you reach the casket, an onscreen prompt asks you to press F to pay your respects. This took on a life of its own, and now on Reddit threads you’ll see people saying press f to pay respects when someone was figuratively killed.
Wow, okay, and they claimed it's not an obscure reference, but you have to have played a certain level in a certain game AND been on a certain forum to know what it means? Maybe obscure doesn't mean what I think it means.
I'm sure there are plenty of people who have used the "press F" meme without knowing the original context too.